Ranolazine Exert its Beneficial Effects in myocardial infarction like Ischemic preconditioning mediators by Increasing Myocardial Nitric oxide, Adenosine, Bradykinin and K+ATPase Levels

Ranolazine Exert its Beneficial Effects in myocardial infarction like Ischemic preconditioning mediators by Increasing Myocardial Nitric oxide, Adenosine, Bradykinin and K+ATPase Levels | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Ranolazine Exert its Beneficial Effects in myocardial infarction like Ischemic preconditioning mediators by Increasing Myocardial Nitric oxide, Adenosine, Bradykinin and K + ATPase Levels Junaid Tantray, Ashish Kumar Sharma, Shivam Singh, Mohammad Zaid, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3825042/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objectives : This study was to investigate cardioprotective effects of ranolazine and to explore possible secondary mechanisms beyond the cellular studies have demonstrated inhibition of late sodium channel(I Na L) leads to reduction in calcium load during cardiac ischemia. We hypothesized that ranolazine-induce Nitric oxide, Adenosine, Bradykinin and K+ATPase like ischemic preconditioning. Methods : Ischemia-reperfusion injury was established using Langendroff’s technique. 20minute ischemia and 40minute reperfusion to coronary artery to isolated heart was model of myocardial infarction. There were following groups: Control(Ischeamia-Reperfusion), Ischemic preconditioning, ranolazine(100µmol/L), ranolazine+L-NAME(30µmol/L) and ranolazine+Aminoguanidine(30µmol/L), ranolazine+Theophylline(50µmol/L), ranolazine+Aminophylline(50µmol/L), ranolazine+Enalapiril(100µmol/L), ranolazine+Losartan(50µmol/L), ranolazine+5-hydroxydecanoate(30µmol/L), ranolazine+glimepiride(50µmol/L) in perfusate. Results : Ranolazine found cardioprotection(Infarct Size:5.334± 0.422 v/s control 65.667±0.558; LDH:101.500±1.147U/L v/s control 155.500±0.957U/L; CK-MB: 100.167±1.302U/L v/s control 198.500±1.803U/L) Ischemic Preconditioning found cardioprotection(Infarct Size:5.1667±0.478 v/s control 65.667±0.558; LDH:101.667±2.789U/L v/s control 155.500±0.958U/L; CK-MB: 97.167±1.721U/L v/s control 198.500±1.803U/L) Ranolazine+L-NAME(Infarct Size:64.167±0.872 v/s control ranolazine 5.334± 0.422; LDH: 154.667±1.256U/L v/s control ranolazine 101.500±1.147; CK-MB:200.167±1.537U/L v/s control ranolizine 100.167±1.302U/L) Ranolazine+Aminoguanidine(Infarct Size: 64.500±0.885 v/s control ranolazine 5.334± 0.422; LDH: 154.833±1.1377U/L v/s control ranolazine 101.500±1.147U/L; CK-MB:198.333±1.145U/L v/s control ranolizine 100.167±1.302U/L) Ranolazine+Theophylline (Infarct Size: 64.667±0.760 v/s control ranolazine 5.334± 0.422; LDH: 155.167±1.301U/L v/s control ranolazine 101.500±1.147; CK-MB:199.167±1.376U/L v/s control ranolizine 100.167±1.302U/L) Ranolazine+Aminophylline (Infarct Size: 65.167±0.601 v/s control ranolazine 5.334± 0.422; LDH: 155.333±0.615U/L v/s control ranolazine 101.500±1.147U/L; CK-MB: 199.500± 1.765U/L v/s control ranolizine 100.167±1.302U/L) Ranolazine+Enalapiril (Infarct Size: 64.667±0.615 v/s control ranolazine 5.334± 0.422; LDH: 154.667± 1.085U/L v/s control ranolazine 101.500±1.147; CK-MB: 201.8333±1.990U/L v/s control ranolizine 100.167±1.302U/L) Ranolazine+Losartan (Infarct Size: 63.667±1.282 v/s control ranolazine 5.334± 0.422; LDH: 155.167± 0.909U/L v/s control ranolazine 101.500±1.147U/L; CK-MB: 199.500±2.349U/L v/s control ranolizine 100.167±1.302U/L) Ranolazine+5-hydroxydecanoate (Infarct Size: 63.833±1.352 v/s control ranolazine 5.334± 0.422; LDH: 154.667±1.054U/L v/s control ranolazine 101.500±1.147; CK-MB: 201.833±1.815U/L v/s control ranolizine 100.167±1.302U/L) Ranolazine+Glimepiride (Infarct Size: 63.667±0.989 v/s control ranolazine 5.334± 0.422; LDH: 155.833±1.352U/L v/s control ranolazine 101.500±1.147U/L; CK-MB: 199.833±1.579U/L v/s control ranolizine 100.167±1.302U/L) Conclusions : As per confirmation Ranolazine and ischemic preconditioning have brought cardioprotection as reduced Infract Size, LDH & CK-MB. Wereas, treatment of L-NAME, Aminoguanidine, Theoplylline, Aminoplylline, Enalapiril, Losartan, 5-hydroxydecanoate & Glimepiride increased infract size, LDH & CK-MB. Hence it is proved that ranolazine involves Nitric oxide, Adenosine, Bradykinin and K+ATPase as secondary messenger in cardioprotection like ischemic preconditioning. Biological sciences/Drug discovery Health sciences/Cardiology Ranolazine Ischemic Preconditioning Nitric Oxide Adenosine Bradykinin K+ATPase Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 1. Introduction According to estimates, 17.5 million people die from cardiovascular diseases each year, accounting for one-third of all deaths globally (World Health Organization, 2016). Major developments in cardiovascular sciences have occurred during the past century, ranging from non-invasive to interventional techniques like coronary artery bypass graft surgery (CABG) and heart transplantation. Cardiovascular diseases remain the leading cause of morbidity and mortality worldwide despite all the progress. The financial strain on the health care system is enormous as a result. The preferred method of treating acute coronary syndrome (ACS) is myocardial reperfusion; however, sudden restoration of blood flow exacerbates tissue damage brought on by ischemia, a condition known as ischemia/reperfusion injury (IRI). Reperfusion-induced imbalance between chemicals that are vasodilators and vasoconstriction is one of the theories put up to explain this phenomenon [ 1 ]. The investigation of a brand-new cardio protection concept has been sparked by efforts to develop ways to prevent and treat this injury. The prevention of permanent myocardial injury and the protection of ventricular dysfunction, which results in heart failure, are the current hot topics of research and discussion. The term "cardio protection" generally refers to all procedures and techniques that lessen or even stop myocardial deterioration and so help to preserve the heart [ 2 ]. Unfortunately, the majority of animal studies, findings could not be replicated in human settings, possibly as a result of fundamental variations in the risk factors and comorbidities involved [ 3 – 4 ]. Numerous research conducted in the last few decades have revealed that the cardiac cells have a number of defense mechanisms to lessen the harm caused by ischemia/reperfusion. These activities provide protection both in the acute phase following ACS and lessen the long-term effects of myocardial infarction since they are not restricted to the myocardium but are also activated at locations both near and far from the heart (MI). Pre-conditioning and post-conditioning are two examples of myocardial cell protection from ischemia/reperfusion occurrences. The cellular mechanisms underlying these phenomena are still unclear, although they are likely to be complex and may involve components from outside the heart [ 5 ]. When first-line antianginal treatments are ineffective at controlling angina symptoms in symptomatic patients, ranolazine is used as an adjunctive treatment. Ranolazine blocks sodium voltage-dependent channels, indicating that the reperfusion process may involve these channels by avoiding the excess salt and calcium that develops during ischemia. In this work, isolated albino Wistar rats were treated to a simulated ischemia and reperfusion regimen in order to assess the effect of ranolazine on cardio protection [ 6 ]. The FDA (Food and Drug Administration) initially authorized ranolazine, a piperazine derivative with a unique mechanism of action, in 2006 for the symptomatic management of patients with chronic angina. Its pharmacological characteristics allow it to make the heart's usage of oxygen more effective by blocking the late Na + current (INaL) in cardiomyocytes and shifting fatty acid oxidation towards glucose oxidation [ 7 – 8 ]. Ranolazine's exact mode of action, however, is not yet fully understood. Ranolazine's therapeutic effects come from its ability to inhibit the Na + influx into cardiac cells through Na + channels, which in pathologic conditions either fail to close after being inactivated [ 9 ]. Additionally, it has been proposed that ranolazine could lessen calcium buildup in cardiac cells during ischemia by blocking the I Na L current [ 10 ]. It is clearly demonstrated clinically that ranolozine and ischeamic precondioning produce cardioprotection. Our research question is whether or not ranolazine induce cardioprotection mimicked are same like ischeamic precondioning mediators. If this research hypothesis is proved, ranolazine as a drug replace clinical surgical procedure of ischemic preconditioning before interventional techniques like coronary artery bypass graft surgery (CABG) and heart transplantation. 2. Material and Methods 2.1 Animals: Wistar Albino Rats used in this study were obtained from Animal House, NIMS University Rajasthan, Jaipur. Wistar Albino Rats (125-150 grams, either sex) were employed in the current study. The rats were given unrestricted access to tap water as well as typical laboratory rat diet. The experimental research protocol has been Ethically approved by the Institutional Animal Ethics Committee (IAEC, 2022) [Protocal No. 01, 02, 03, 05, & 08], NIMS University Rajasthan, Jaipur, Rajasthan, India, Registration No. 1203/PO/Re/S/09/CPCSEA, under the supervision of CPCSEA, Government of India, New Delhi, India. - I confirm that all methods were carried out in accordance with relevant guidelines and regulations (Government of India Guidelines- Ministry of Fisheries, Animal Husbandry and Dairying, C/o Committee for purpose of Control and Supervision of Experiments on Animals [CPCSEA]) . - I confirm that all methods are reported in accordance with ARRIVE guidelines (https://arriveguidelines.org). 2.2 Drugs & Chemicals The drugs and chemicals which are used during experimental procedure are mentioned below (Table 1): Table 1: Drugs & Chemicals and their Procurement S.NO. Drug Name Procurement 1. Ranolazine Glenmark Pharmaceuticals Limited, Maharashtra. 2. Ketamine Troika Pharmaceuticals Limited, Uttarakhand, India. 3 L-NAME (N ώ -nitro-L-arginine methyl ester) Tokyo Chemical Industry Co. Ltd., Toshima, Kita-Ku., Tokya, Japan 4. Aminoguanidine BLD Pharmatech (India) Pvt. Ltd., Hyderabad. 501401, Telangana, INDIA 5. Theophylline Zydus Healthcare Limited, Hyderabad India 6. Aminophylline Rathi Laboratories, Patna, India. 7. Enalapril Maleate BATCH NO. EMI-1118054, VENDOR: NEULAND LABORATORIES LTD. R&D, Medley Pharmaceuticals Ltd., Mumbai, India 8. LOSARTAN POTASSIUM USP (1000272) BATCH NO. 1943109612, VENDOR: VASUDHA PHARMA CHEM LIMITED R&D, Medley Pharmaceuticals Ltd., Mumbai, India 9. 5-Hydroxydeconate BLD Pharmatech Limited, Telegana, India 10. Glimepride Medely Pharmaceuticals Ltd. Mumbai. India 11. Heparin BE Pharmaceuticals Private Limited, Telangana India. 12. Triphenyl tetrazolium Chloride BLD Pharmatech (India) Private Limited, Telangana India. 13. NaHCO 3 , NaH 2 PO 4 Qualikems Fine Chem Private Limited, Vadodara India 14. MgSO 4 , CaCl 2 , Diethyl ether, Carboxymethylcellulose Central Drug Store (P) Limited. Ne Indiaw Delhi 15. KCl, Dextrose, NaCl Ases Chemicals, Jodhpur, India. 16. Na 2 HPO 4 RFCL Limited, New Delhi. India 2.3 Biomarkers-LDH, CK-MB [12] Myocardial infarction leads to an increase in the serum isoenzyme of myocardial-associated creatine kinase (CK-MB) and the isoenzyme serum lactate dehydrogenase (LDH). Because the atrial myocardium contains the same amount of CK-MB as the ventricular myocardium, surgical manipulation of the atrium in the postoperative period can result in elevated serum CK-MB levels [11]. The distribution of the LDH isoenzymes is different in the myocardium of the atria and ventricles. Elevated serum enzymes due to myocardial necrosis are considered a specific finding of myocardial infarction. The aim of this study was to determine the changes in the concentrations of LDH, CK-MB isoenzymes in animals after coronary artery bypass graft implantation and after atriotomy for surgical correction without symptoms of myocardial infarction who have been diagnosed on the basis of clinical studies, hemodynamic and electrocardiographic results. CK-MB, LDH, show significant elevations resembling perioperative myocardial infarction [12]. 2.4 Infarct Size Measurement [13] Infract size measurement was carried by two methods By volume method By weight method By volume method The slices were placed between two glass plates. A transparent plastic grid with 100 squares of 1 cm 2 was placed on top. The mean area of each slice was calculated by counting the number of squares on either side. Likewise, the number of squares falling on the yellow part was also counted. The infarct surface was expressed as a percentage of the total surface [13]. By weight method All slices were weighed. The yellow infarct portion was removed and weighed. Infarct size was expressed as a percentage of total weight. By the two mentioned methods percentage infarction in hearts of five groups have been measured[13]. 2.5 Surgical preparations Apparatus- Langendorff's apparatus (INCO, Ambala, India), ECG (BPL CARDIAART 108TDIGI, New Delhi, India) The Langendorff cardiac test, or isolated perfused cardiac test, is an ex vivo technique used in pharmacological and physiological studies in animals and humans. This technique, named after the German physiologist Oskar Langendorff, allows the study of cardiac muscle contractile force and heart rate without the complications encountered in intact animals or humans [14]. In the Langendorff preparation, the heart is removed from the animal or human body by severing the blood vessels. This is followed by reverse perfusion (retrograde perfusion) through the aorta, usually with a nutrient-rich oxygen-containing solution ( Krebs-Henseleit solution)[13]. 2.6 Procedure[13] Rats anaesthetized with ketamine 100mg/kg Limb lead II ECG installed and rat chest was opened. Heparin (500 IU, i.p.) was administered just under 15 minutes before animal sacrificed. Heart was exposed and pericardium was removed. The heart was quickly removed and was immediately mounted on the Langendorff apparatus. The aorta was retrogradely perfused under constant pressure70 mmHg with Krebs-Henseleit buffer (118 mM NaCl; KCl 4.7 mM; CaCl 2 2.5 mM; MgSO 4 .7H 2 O 1.2 mM ; NaHCO 3 25 mM; KH 2 PO 4 1.2 mM; C 6 H 12 O 6 11 mM) was retrogradely perfused into the aorta under continuous pressure of 70mmHg while bubbling with 95% O 2 and 5% CO 2 . The heart was surrounded by a double-walled coat, whose temperature was maintained by circulation water was heated to 37°C Ischemia ensued 20-minute respected by reperfusion for 40 minutes. Electrocardiography (ECG) (GLP-CARDIAART 108T-DIGI, New Delhi, India) was made using two silver electrodes attached to the apex of the left ventricle and apex of right auricle. ECG recording immediately after stabilization, 0, 10 and 20-minutes during ischemia and immediately, 0, 10,20, 30 and 40 minutes after reperfusion. Left anterior descending coronary artery was ligated for 20 min ischemia by passing 4/0 silken thread and is being tied by shoelace knot. After 20 min of ischemia 40min of reperfusion was done. The above is the protocol of ischemia reperfusion injury. Coronary effusion was collected at the end of reperfusion for the determination of lactate dehydrogenase (LDH) & CK-MB. After ischemia reperfusion injury heart was excised, aorta and auricles removed and heart was frozen in deep freeze. After 24hrs heart was removed from freezer and 1mm thickness slices of heart was made. Then stained with TTC (Triphenyl tetrazolium chloride) and Evan’s Blue at 37ºC in incubator. After 10min stained slices has been washed with saline and placed in between two glass plates. Graph transparency was put on the glass plate and infarct size was calculated by volume method and after that, infarct size was calculated by weight method. The pre-treatment of drugs before ischemia reperfusion injury model was done to elucidate mechanism of action of drugs. 2.7 Experimental protocol (Table 2) There were 30 wistar albino rats utilized in this investigation, divided into six groups with an average of six animals per group (n=6). Table 2: Different type of groups with number of animals S.NO GROUP NO. of Animals I Control (Ischeamia-reperfusion) n=6 II Ischeamic preconditioning n=6 III Ranolazine n=6 IV Ranolazine and L-NAME n=6 V Ranolazine and Aminoguanidine n=6 VI Ranolazine and Theoplylline n=6 VII Ranolazine and Aminoplylline n=6 VII Ranolazine and Enalapril n=6 IX Ranolazine and Losartan n=6 X Ranolazine and 5-hydroxydecanoate n=6 XI Ranolazine and Glimepiride n=6 Group I: The control group (ischemia-reperfusion) First the rat has been anaesthetized with ketamine 100mg/kg, Limblead II ECG installed & Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Group II: Group for ischemic preconditioning Before ischemia-reperfusion, heart underwent an ischemic preconditioning programme. First the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed & Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Group III: Pre-treatment of Ranolazine drug First the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed & Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100µmol/L) were added in Physiological salt solution (PSS) earlier. Group IV: Ranolazine and L-NAME First the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed & Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100µmol/L) and L-NAME drug (30µmol/L) were added in Physiological salt solution (PSS) earlier. Group V: Ranolazine and Aminoguanidine First the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed & Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100µmol/L) and Aminoguanidine(30µmol/L) drug were added in Physiological salt solution (PSS) earlier. Group VI: Ranolazine and Theophylline First the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed & Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100µmol/L) and Theophylline drug (50µmol/L) were added in Physiological salt solution (PSS) earlier. Group VII: Ranolazine and Aminophylline First the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed & Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100µmol/L) and Aminophylline(50µmol/L) drug were added in Physiological salt solution (PSS) earlier. Group VIII: Ranolazine and Enalapril First the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed & Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100µmol/L) and Enalapril drug (100µmol/L) were added in Physiological salt solution (PSS) earlier. Group IX: Ranolazine and Losartan First the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed & Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100µmol/L) and Losartan(50µmol/L) drug were added in Physiological salt solution (PSS) earlier. Group X: Ranolazine and 5-Hydroxydecanoate First the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed & Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100µmol/L) and 5-Hydroxydecanoate drug (30µmol/L) were added in Physiological salt solution (PSS) earlier. Group XI: Ranolazine and Gimepiride First the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed & Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100µmol/L) and Glimepiride(50µmol/L) drug were added in Physiological salt solution (PSS) earlier. 2.8 Staining procedure The heart was removed from Langendorff’s apparatus. It was kept in refrigerator for 24 hours. Then the 1mm slices of frozen heart were made. The slices of heart were stained with TTC (Triphenyl tetrazolium chloride) and Evan’s Blue and kept in BOD incubator for 10 minutes. After 10 min the slices were removed from incubator and infract size was measured after washing by saline[13] . 2.9. Estimation of LDH and CK-MB 2.9.1 LDH- Lactate dehydrogenase (LDH) assay (Figure 1) LDH was measured in coronary fluid using the integrated VITROUS system 5600 apparatus. Principle - LDH catalyzes the following reaction: lactate þ NAD $ pyruvate þ NADH: The pyruvate thus formed is coupled with 2,4-DNPH to the corresponding hydrazone, which gives a brown color in alkaline medium. The intensity of this color is proportional to the amount of LDH activity and is measured spectrophotometrically at 440 nm. 2.9.2 Creatine Phosphokinase (CK) Assay (Figure 1) The creatine phosphokinase (CPK) concentration was determined in the coronary fluid also using the integrated VITROUS system 5600 apparatus. Principle- It catalyzes the following reaction: creatine phosphate þ ADP $ creatine þ ATP: At pH 7.4, CPK catalyzes the forward reaction. The resulting creatine reacts with diacetyl and naphthol in alkaline medium, resulting in a pink color. The intensity of this color is proportional to the enzymatic activity and is measured spectrophotometrically at 520 nm. Mg2+ and cysteine are added as activators. The p-chloromercuric benzoate stops the reaction by inactivating the enzyme [13]. 2.10 Statistical Analysis Values for enzymatic data and infract size were expressed as Mean ± standard error of the mean (SEM). Statistical significance was calculated using one-way analysis of variance. Dunnett’s test and student’s t-test were employed as post hoc testes for comparision with the control group and multiple comparisions between groups, respectively. A value of P < 0.05 is considered to be statistically significant. SigmaPlot v15 software was used for statistical analysis. 3. Results 3.1 Effect of Control (ischeamia-reperfusion) and ischemic preconditioning group on myocardial infarction, LDH & CK-MB (Figure 2, 3 & 4); (Table 3, 4 & 5) In ischemic preconditioning group myocardial infarct size decreases significantly as compared to control (ischeamia-reperfusion) group. The myocardial infarction in control group was found to be of 65.667±0.558 and myocardial infarction in ischemic preconditioning group was found to be 5.1667±0.478. The LDH in control group was found to be of 155.500±0.958and LDH in ischemic preconditioning group was found to be 101.667±2.789. The CK-MB in control group was found to be of 198.500±1.803 and CK-MB in ischemic preconditioning group was found to be 97.167±1.721. 3.2 Effect of Control (ischeamia-reperfusion) and Ranolazine treatment group on myocardial infarction, LDH & CK-MB (Figure 2, 3 & 4); (Table 3, 4 & 5) In Ranolazine treatment group myocardial infarct size decreases significantly as compared to control (ischeamia-reperfusion) group. The myocardial infarction in control group was found to be of 65.667±0.558 and myocardial infarction in Ranolazine treatment group was found to be 5.334± 0.422. The LDH in control group was found to be of 155.500±0.958and LDH in ranolazine treatment group was found to be 101.500±1.147. The CK-MB in control group was found to be of 198.500±1.803 and CK-MB in ranolazine treatment group was found to be 100.167±1.302. 3.3 Effect of Ranolazine and Ranolazine+L-NAME (Nitric oxide synthase inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 & 4); (Table 3, 4 & 5) L-NAME being a Nitric oxide synthase inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug. The myocardial infarction in Ranolazine+L-NAME group was found to be of 64.167±0.872 and myocardial infarction in Ranolazine treatment group was found to be 5.334± 0.422. The LDH in Ranolazine+L-NAME group was found to be of 154.667±1.256 and LDH in ranolazine treatment group was found to be 101.500±1.147. The CK-MB in Ranolazine+L-NAME group was found to be of 200.167±1.537 and CK-MB in ranolazine treatment group was found to be 100.167±1.302. 3.4 Effect of Ranolazine and Ranolazine+Aminoguanidine (Nitric oxide synthase inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 & 4); (Table 3, 4 & 5) Aminoguanidine being a Nitric oxide synthase inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug. The myocardial infarction in Ranolazine+Aminoguanidine group was found to be of 64.500±0.885 and myocardial infarction in Ranolazine treatment group was found to be 5.334± 0.422. The LDH in Ranolazine+Aminoguanidine group was found to be of 154.833±1.1377and LDH in ranolazine treatment group was found to be 101.500±1.147. The CK-MB in Ranolazine+Aminoguanidine group was found to be of 198.333±1.145and CK-MB in ranolazine treatment group was found to be 100.167±1.302. 3.5 Effect of Ranolazine and Ranolazine+Theophylline (Adenosine inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 & 4); (Table 3, 4 & 5) Theoplylline being an adenosine inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+Theophylline group was found to be of 64.667±0.760 and myocardial infarction in Ranolazine treatment group was found to be 5.334± 0.422. The LDH in Ranolazine+Theophylline group was found to be of 155.167±1.301 and LDH in ranolazine treatment group was found to be 101.500±1.147. The CK-MB in Ranolazine+Theophylline group was found to be of 199.167±1.376 and CK-MB in ranolazine treatment group was found to be 100.167±1.302. 3.6 Effect of Ranolazine and Ranolazine+Aminophylline (Adenosine inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 & 4); (Table 3, 4 & 5) Aminophylline being an adenosine inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+Aminophylline group was found to be of 65.167±0.601 and myocardial infarction in Ranolazine treatment group was found to be 5.334± 0.422. The LDH in Ranolazine+Aminophylline group was found to be of 155.333±0.615 and LDH in ranolazine treatment group was found to be 101.500±1.147. The CK-MB in Ranolazine+Aminophylline group was found to be of 199.500± 1.765 and CK-MB in ranolazine treatment group was found to be 100.167±1.302. 3.7 Effect of Ranolazine and Ranolazine+Enalapril (Bradykinin inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 & 4); (Table 3, 4 & 5) Enalapril being an bradykinin inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+Enalapril group was found to be of 64.667±0.615 and myocardial infarction in Ranolazine treatment group was found to be 5.334± 0.422. The LDH in Ranolazine+Enalapril group was found to be of 154.667± 1.085 and LDH in ranolazine treatment group was found to be 101.500±1.147. The CK-MB in Ranolazine+Enalapril group was found to be of 201.8333±1.990 and CK-MB in ranolazine treatment group was found to be 100.167±1.302. 3.8 Effect of Ranolazine and Ranolazine+Losartan (Bradykinin inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 & 4); (Table 3, 4 & 5) Losartan being an bradykinin inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+Losartan group was found to be of 63.667±1.282 and myocardial infarction in Ranolazine treatment group was found to be 5.334± 0.422. The LDH in Ranolazine+Losartan group was found to be of 155.167±0.909and LDH in ranolazine treatment group was found to be 101.500±1.147. The CK-MB in Ranolazine+Losartan group was found to be of 199.500±2.349 and CK-MB in ranolazine treatment group was found to be 100.167±1.302. 3.9 Effect of Ranolazine and Ranolazine+5-Hydroxydecanoate(K + ATPase inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 & 4); (Table 3, 4 & 5) 5-Hydroxydecanoate a K + ATPase inhibitor, increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+5-Hydroxydecanoate group was found to be of 63.833±1.352 and myocardial infarction in Ranolazine treatment group was found to be 5.334± 0.422. The LDH in Ranolazine+5-Hydroxydecanoate group was found to be of 154.667±1.054 and LDH in ranolazine treatment group was found to be 101.500±1.147. The CK-MB in Ranolazine+5-Hydroxydecanoate group was found to be of 201.833±1.815 and CK-MB in ranolazine treatment group was found to be 100.167±1.302. 3.10 Effect of Ranolazine and Ranolazine+Glimepiride(K + ATPase inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 & 4); (Table 3, 4 & 5) Glimepiride a K + ATPase inhibitor, increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+Glimepiride group was found to be of 63.667±0.989 and myocardial infarction in Ranolazine treatment group was found to be 5.334± 0.422. The LDH in Ranolazine+Glimepiride group was found to be of 155.833±1.352and LDH in ranolazine treatment group was found to be 101.500±1.147. The CK-MB in Ranolazine+Glimepiride group was found to be of 199.833±1.579 and CK-MB in ranolazine treatment group was found to be 100.167±1.302. Table 3: Myocardial infarct size of different group of animals S.No. Groups Groups Description Infarct Size 1. I Control(Ischeamia-Reperfusion) 65.667±0.558 2. II Ischemic preconditioning 5.1667±0.47***a 3. III Ranolazine 5.334±0.422 ***b 4. IV Ranolazine+ L-NAME 64.167±0.872***c 5. V Ranolazine+Aminoguanidine 64.500±0.885 ***d 6 VI Ranolazine and Theoplylline 64.667±0.760***e 7 VII Ranolazine and Aminoplylline 65.167±0.601***f 8 VII Ranolazine and Enalapril 64.667±0.615***g 9 IX Ranolazine and Losartan 63.667±1.282***h 10 X Ranolazine and 5-hydroxydecanoate 63.833±1.352***i 11 XI Ranolazine and Glimepiride 63.667±0.989***j Infarct size of rat’s heart: Values are Mean± SEM of five experiments, (n=6). Here P>0.05 denotes non-significant value, *p≤0.05 denotes significant value, **P<0.01 denotes very significant value, ***P<0.001 denotes extremely significant value. a-indicates comparison between Group I & Group II(P<0.05), b-indicates comparison between Group I & Group III(P<0.05), c indicates comparison between Group IV vs Group III(P<0.05), d indicates comparison between Group V & Group III(P<0.05). e-indicates comparison between Group VI & Group III(P<0.05), f-indicates comparison between Group VII & Group III(P<0.05), g indicates comparison between Group VIII vs Group III(P<0.05), h indicates comparison between Group IX & Group III(P<0.05). i-indicates comparison between Group X & Group III(P<0.05), j-indicates comparison between Group XI & Group III(P0.05 denotes non-significant value, *p≤0.05 denotes significant value, **P<0.01 denotes very significant value, ***P<0.001 denotes extremely significant value. a-indicates comparison between Group I (Control-ischeamia-reperfusion) & Group II(ischeamic preconditioning)(P<0.05), b-indicates comparison between Group I(Control-ischeamia-reperfusion) & Group III(Ranolazine)(P<0.05), c indicates comparison between Group IV(Ranolazine+L-NAME) vs Group III(Ranolazine)(P<0.05), d indicates comparison between Group V(Ranolazine+Aminoguanidine) & Group III(Ranolazine) (P<0.05). e-indicates comparison between Group VI(Ranolazine+Theophylline) & Group III(Ranolazine) (P<0.05), f-indicates comparison between Group VII(Ranolazine+Aminophylline) & Group III(Ranolazine) (P<0.05), g indicates comparison between Group VIII(Enalapril) vs Group III(Ranolazine) (P<0.05), h indicates comparison between Group IX(Ranolazine+Losartan) & Group III(Ranolazine) (P<0.05). i-indicates comparison between Group X(Ranolazine+5-Hydroxy Decanoate) & Group III(Ranolazine) (P<0.05), j-indicates comparison between Group XI(Ranolazine+Glimepiride) & Group III(Ranolazine)(P<0.05). Table 4: Lactate dehydrogenase (LDH) release in coronary effluent of isolated rat heart at 40 minute reperfusion S.No. Groups Groups Description Lactate dehydrogenase (LDH) at 40 minute reperfusion 1. I Control(Ischeamia-Reperfusion) 155.500±0.957 2. II Ischemic preconditioning 101.667±2.789***a 3. III Ranolazine 101.500±1.147***b 4. IV Ranolazine+ L-NAME 154.667±1.256***c 5. V Ranolazine+Aminoguanidine 154.833±1.1377***d 6 VI Ranolazine and Theoplylline 155.167±1.301708***e 7 VII Ranolazine and Aminoplylline 155.333±0.615***f 8 VII Ranolazine and Enalapril 154.667± 1.085***g 9 IX Ranolazine and Losartan 155.167± 0.909***h 10 X Ranolazine and 5-hydroxydecanoate 154.667±1.054***i 11 XI Ranolazine and Glimepiride 155.833±1.352***j Lactate dehydrogenase (LDH) release in coronary effluent of isolated rat heart at 40 minute reperfusion: Values are Mean± SEM of five experiments, (n=6). Here P>0.05 denotes non-significant value, *p≤0.05 denotes significant value, **P<0.01 denotes very significant value, ***P<0.001 denotes extremely significant value, a-indicates comparison between Group I & Group II, b-indicates comparison between Group I & Group III, c indicates comparison between Group IV vs Group III, d indicates comparison between Group V & Group III. e-indicates comparison between Group VI & Group III, f-indicates comparison between Group VII & Group III, g indicates comparison between Group VIII vs Group III, h indicates comparison between Group IX & Group III. i-indicates comparison between Group X & Group III, j-indicates comparison between Group XI & Group III. Figure 3: Lactate dehydrogenase (LDH) release in coronary effluent of isolated rat heart at 40 minute reperfusion Lactate dehydrogenase (LDH) release in coronary effluent of isolated rat heart at 40 minute reperfusion: Values are Mean± SEM of five experiments, (n=6). Here P>0.05 denotes non-significant value, *p≤0.05 denotes significant value, **P<0.01 denotes very significant value, ***P<0.001 denotes extremely significant value. a-indicates comparison between Group I (Control-ischeamia-reperfusion) & Group II(ischeamic preconditioning)(P<0.05), b-indicates comparison between Group I(Control-ischeamia-reperfusion) & Group III(Ranolazine)(P<0.05), c indicates comparison between Group IV(Ranolazine+L-NAME) vs Group III(Ranolazine)(P<0.05), d indicates comparison between Group V(Ranolazine+Aminoguanidine) & Group III(Ranolazine) (P<0.05). e-indicates comparison between Group VI(Ranolazine+Theophylline) & Group III(Ranolazine) (P<0.05), f-indicates comparison between Group VII(Ranolazine+Aminophylline) & Group III(Ranolazine) (P<0.05), g indicates comparison between Group VIII(Enalapril) vs Group III(Ranolazine) (P<0.05), h indicates comparison between Group IX(Ranolazine+Losartan) & Group III(Ranolazine) (P<0.05). i-indicates comparison between Group X(Ranolazine+5-Hydroxy Decanoate) & Group III(Ranolazine) (P<0.05), j-indicates comparison between Group XI(Ranolazine+Glimepiride) & Group III(Ranolazine)(P<0.05). Table 5: Creatine kinase myoglobin binding (CK-MB) release in coronary effluent of isolated rat heart at 40 minute reperfusion. S.No. Groups Groups Description Lactate dehydrogenase (LDH) at 40 minute reperfusion 1. I Control(Ischeamia-Reperfusion) 198.500±1.803 2. II Ischemic preconditioning 97.167±1.721***a 3. III Ranolazine 100.167±1.302***b 4. IV Ranolazine+ L-NAME 200.167±1.537***c 5. V Ranolazine+Aminoguanidine 198.333±1.145***d 6 VI Ranolazine and Theoplylline 199.167±1.376***e 7 VII Ranolazine and Aminoplylline 199.500± 1.765***f 8 VII Ranolazine and Enalapril 201.8333±1.990***g 9 IX Ranolazine and Losartan 199.500±2.349***h 10 X Ranolazine and 5-hydroxydecanoate 201.833±1.815***i 11 XI Ranolazine and Glimepiride 199.833±1.579***j Creatine kinase myoglobin binding (CK-MB) release in coronary effluent of isolated rat heart at 40 minute reperfusion: Values are Mean± SEM of five experiments, (n=6). Here P>0.05 denotes non-significant value, *p≤0.05 denotes significant value, **P<0.01 denotes very significant value, ***P<0.001 denotes extremely significant value, a-indicates comparison between Group I & Group II, b-indicates comparison between Group I & Group III, c indicates comparison between Group IV vs Group III, d indicates comparison between Group V & Group III. e-indicates comparison between Group VI & Group III, f-indicates comparison between Group VII & Group III, g indicates comparison between Group VIII vs Group III, h indicates comparison between Group IX & Group III. i-indicates comparison between Group X & Group III, j-indicates comparison between Group XI & Group III. Creatine kinase myoglobin binding (CK-MB) release in coronary effluent of isolated rat heart at 40 minute reperfusion: Values are Mean± SEM of five experiments, (n=6). Here P>0.05 denotes non-significant value, *p≤0.05 denotes significant value, **P<0.01 denotes very significant value, ***P<0.001 denotes extremely significant value. a-indicates comparison between Group I (Control-ischeamia-reperfusion) & Group II(ischeamic preconditioning)(P<0.05), b-indicates comparison between Group I(Control-ischeamia-reperfusion) & Group III(Ranolazine)(P<0.05), c indicates comparison between Group IV(Ranolazine+L-NAME) vs Group III(Ranolazine)(P<0.05), d indicates comparison between Group V(Ranolazine+Aminoguanidine) & Group III(Ranolazine) (P<0.05). e-indicates comparison between Group VI(Ranolazine+Theophylline) & Group III(Ranolazine) (P<0.05), f-indicates comparison between Group VII(Ranolazine+Aminophylline) & Group III(Ranolazine) (P<0.05), g indicates comparison between Group VIII(Enalapril) vs Group III(Ranolazine) (P<0.05), h indicates comparison between Group IX(Ranolazine+Losartan) & Group III(Ranolazine) (P<0.05). i-indicates comparison between Group X(Ranolazine+5-Hydroxy Decanoate) & Group III(Ranolazine) (P<0.05), j-indicates comparison between Group XI(Ranolazine+Glimepiride) & Group III(Ranolazine)(P<0.05). 4. Discussion Mechanism of action of Ranolazine Numerous studies demonstrated ranolazine as cardioproective in clinical as well as in animal studies [15-17]. In its Ranolazine Ischemia Na+ Overload Mechanical dysfunction ↑ diastolic tension ↓ contractility Ca2+ Overload Electrical Dysfunction Arrhythmias NCX ↑ late INa Na/K-ATPase NHE O2 Supply & Demand ↑ ATP consumption ↓ ATP formation. Late INa under normal and increased late INa under pathophysiological conditions, late INa inhibition with ranolazine reverse mode (usually during the action potential), it brings in calcium into the cell in exchange to trans-sarcolemma elimination of sodium. The activity and direction of transport depends on the abundance of the protein as well as on the membrane potential, intracellular sodium and intracellular calcium concentration. Sodium accumulation following myocardial hypoxia (i.e., through late INa) promotes reverse mode sodium–calcium exchange and therefore reduces the overall cellular capacity to eliminate calcium outside of the cytosol (Figure 5; Figure 6) [14-17]. Ischemic Pre-conditioning and its mediators Ischemia is defined as a state in which the blood flow is partially or completely blocked in a tissue or organ. When ischemia persists, necrosis and cell death occur. reperfusion injury (IRI). Renal IRI is one of the main causes of acute kidney injury and occurs in various clinical situations, such as partial nephrectomy, renal transplantation, aortic cross clamping surgery, cardiopulmonary resuscitation, sepsis, and shock. Hydrogen sulfide, superoxide dismutase (SOD), apocynin, allopurinol, hypothermia, ischemic preconditioning (IPC), and remote ischemic preconditioning (RIPC) were found to reduce IRI. Remote ischemic preconditioning, in which the IPC of one organ protects another distant organ against prolonged IRI, may attenuate renal injury induced by IRI. Brief ischemia and reperfusion produce large amounts of oxygen-derived free radicals, which in turn release antioxidants that act as free radical scavengers. Although the underlying protective mechanisms of RIPC have not been fully understood, nitric oxide (NO) generated by RIPC is considered to have a protective effect against IRI of the heart, brain, and liver (Figure 7) [18]. Role of nitric oxide, adenosine, Bradykinin & K + ATPase has been previously reported in ischemic preconditioning that have cardioprotective effect [19-41]. Previous findings about CK-MB and LDH in cardioprotection CK-MB and LDH are widely used as markers to assess the extent of myocardial damage and ischemia-reperfusion injury. In the context of cardioprotective research, they serve as valuable indicators of the effectiveness of various interventions, including preparedness strategies, pharmacological agents, and other therapeutic approaches to minimize tissue damage in ischemic events. In conclusion, both CK-MB and LDH play an important role as markers of myocardial and cellular damage in cardioprotective studies. Monitoring their levels can shed light on the effects of various harm reduction strategies and interventions in ischemia-reperfusion injury [42]. Ischemic preconditioning and Ranolazine has demonstrated cardioprotection because they have decreased LDH and CK-MB in ischemic reperfusion induced cardiac injury. As per previous literature ischemic preconditioning has brought cardioprotection by nitric oxide, adenosine, bradykinin and K + ATPase mediated pathway. Now our research question is that Ranolazine is also mediating cardioprotection by these pathways. However it is confirmed that adenosine levels are increased in ranolazine induced cardioprotection in dogs [24]. Our study confirms that Ranolazine induced cardioprotection involves nitric oxide, adenosine, bradykinin and K + ATPase mediated pathway as L-NAME, Aminoguanidine, Theophylline, Aminophylline, Enalapril, Losartan, 5-Hydroxydecanoate and Glimepiride abolished ranolazine induced cardioprotection. L-NAME, Aminoguanidine, Theophylline, Aminophylline, Enalapril, Losartan, 5-Hydroxydecanoate and Glimepiride increases infarct size, LDH and CK-MB in ranolazine treatment groups. Hence, in conclusion our research findings suggest role of nitric oxide, adenosine, bradykinin and K + ATPase in Ranolazine induced cardioprotection as secondary messenger like ischemic preconditioning. Hence ranolazine as drug can replace surgical ischemic preconditioning before interventional techniques like coronary artery bypass graft surgery (CABG) and heart transplantation for better patient compliance. 5. Conclusion In Ranolazine treated group with both nitric oxide inhibitors - L-NAME and aminoguanidine, both adenosine inhibitors- Theophylline and Aminophylline, both Bradykinin inhibitors- Enalapril and Losartan & both K + ATPase inhibitors- 5-Hydroxydecanoate and Glimepiride treatment group increased percentage myocardial infarction, lactate dehydrogenase, and CK-MB. Hence, in conclusion our research findings suggest role of nitric oxide, adenosine, bradykinin and K + ATPase in cardioprotection as secondary messenger in ischeamic preconditioning. As a result, we also conclude that nitric oxide, adenosine, bradykinin and K + ATPase function as a secondary messenger in the cardioprotection caused by ranolazine. Hence ranolazine as drug can replace surgical ischemic preconditioning and used in ischemic heart disease and before interventional techniques like coronary artery bypass graft surgery (CABG) and heart transplantation for better patient compliance. Declarations Author Contribution All Authors contributed to execute experimental, manuscript preparation, data analysis, litrature survey etc. Data availability statement The datasets used and/or analysed during the current study available from the corresponding author on reasonable request. “Availability of Data and Materials” statements: All authors declare that excel sheet raw data and supplementary files (Ethical approvals from Indian Government approved for experiments on vertebrates [Wistar Albino Rats] has been attached as supplementary files to be shared in the said manuscript. "Authors reporting experiments on live vertebrates have included the appropriate ethics declarations in the Methods section of our manuscript”. We checked that the information provided is unambiguous using the following requirements: - I confirm that all methods were carried out in accordance with relevant guidelines and regulations . - I confirm that all methods are reported in accordance with ARRIVE guidelines (https://arriveguidelines.org). For further information, I have gone through guidelines using the following link & the research is in accordance to these policies: https://www.nature.com/srep/journal-policies/editorial-policies#experimental-subjects References Li, J., Zhang, H. & Zhang, C. Role of inflammation in the regulation of coronary blood flow in ischemia and reperfusion: mechanisms and therapeutic implications. J Mol Cell Cardiol 52(4), 865–72. doi: 10.1016/j.yjmcc.2011.08.027 (2012). Kubler, W. & Haass, M. Cardioprotection: definition, classification, and fundamental principles. Heart 75(4), 330–3. doi: 10.1136/hrt.75.4.330 (1996). Dirksen, M.T., Laarman, G.J., Simoons, M.L. & Duncker, D.J. Reperfusion injury in humans: a review of clinical trials on reperfusion injury inhibitory strategies. Cardiovasc Res 74(3), 343–55. doi: 10.1016/j.cardiores.2007.01.014 (2007). McCafferty, K., Forbes, S., Thiemermann, C. & Yaqoob, M.M. The challenge of translating ischemic conditioning from animal models to humans: the role of comorbidities. Dis Model Mech 7(12), 1321–33. doi: 10.1242/dmm.016741 (2014). Gattullo, D., Linden, R.J., Losano, G., Pagliaro, P. & Westerhof, N. Ischaemic preconditioning changes the pattern of coronary reactive hyperaemia in the goat: role of adenosine and nitric oxide. Cardiovasc Res 42(1), 57–64. doi: 10.1016/s0008-6363(98)00319-8 (1999). Calderón-Sánchez, E.M., Domínguez-Rodríguez, A., López-Haldón, J., Jiménez-Navarro, M.F., Gómez, A.M., Smani, T. & Ordóñez, A. Cardioprotective Effect of Ranolazine in the Process of Ischemia-reperfusion in Adult Rat Cardiomyocytes. Rev Esp Cardiol (Engl Ed). 69(1), 45–53. doi: 10.1016/j.rec.2015.02.027 (2016 Jan). Hale, S.L., Leeka, J.A. & Kloner, R.A. Improved Left Ventricular Function and Reduced Necrosis after Myocardial Ischemia/Reperfusion in Rabbits Treated with Ranolazine, an Inhibitor of the Late Sodium Channel. J Pharmacol Exp Ther. 318(1), 418–23. doi: 10.1124/jpet.106.103242 (2006). Cheng, J.W. Ranolazine for the management of coronary artery disease. Clin Ther . 28(12),1996–2007. doi: 10.1016/j.clinthera.2006.12.009 (2006) Belardinelli, L., Shryock, J.C. & Fraser H. The mechanism of ranolazine action to reduce ischemia-induced diastolic dysfunction. Eur Heart J Suppl. 8(Suppl_A), A10–3. doi: 10.1093/EURHEART/SUI091 (2006). Rayner-Hartley, E. & Sedlak, T. Ranolazine: a contemporary review. Journal of the American Heart Association. 5(3), e003196. doi: 10.1161/JAHA.116.003196 (2016). Nilsson, B.O. Biological effects of aminoguanidine: an update. Inflamm Res. 48(10), 509–15. doi: 10.1007/s000110050495 . doi: 10.1007/s000110050495 (1999) Wolf, R.E., Graeber, G.M., Burge, J.R., DeShong, J.L., MacDonald, J.L. & Zajtchuk, R. Evaluation of Serum Creatine Kinase and Lactate Dehydrogenase in Experimental Myocardial Infarction, Atriotomies, and Thoracotomies. The Annals of Thoracic Surgery. 41(4), 378–386, https://doi.org/10.1016/S0003-4975(10)62690-2 (1986). [15]. Sharma, A.K., Munajjam, A., Vaishnav, B., Sharma, R., Kishore, K., Sharma, A., Sharma, D., Kumari, R., Tiwari, A. & Srinivasan, B.P. Remote preconditioning by aortic constriction: Does it afford cardioprotection similar to classical or other remote ischemic preconditioning? Role of inducible nitric oxide synthase. CVD Prevention and Control. 6(1), 15–33. doi: 10.1016/S1674-8301(12)60004-9 (2011). Langendorff, O. Untersuchugen am uberlebenden Saugethieherzen. Pflugers Arch. 61, 291–307. (1895) [13]. Kutsal, A., Saydam, G.S., Yücel, D. & Balk, M. Changes in the serum levels of CK-MB, LDH, LDH1, SGOT and myoglobin due to cardiac surgery. J Cardiovasc Surg (Torino). 32(4), 516–22. PMID: 1864883 (1991). [14]. Jung, H., Choi, E.K., Baek, S.I., Cho, C., Jin, Y., Kwak, K.H., Jeon, Y., Park, S.S., Kim, S. & Lim, D.G. The effect of nitric oxide on remote ischemic preconditioning in renal ischemia reperfusion injury in rats. Dose-Response. 17(2), 1559325819853651. doi: 10.1177/1559325819853651 (2019). Efentakis, P., Andreadou, I., Sophia-Iris, B., Vasileiou, S., Dagres, N., Zoga, A., Lougiakis, N., Kremastinos, D.T. & Iliodromitis, E.K. Ranolazine triggers pharmacological preconditioning and postconditioning in anesthetized rabbits through activation of RISK pathway. Eur J Pharmacol. 789, 431–438. doi: 10.1016/j.ejphar.2016.08.001 (2016). Tawfik, M.K. & Ameen, A.M. Cardioprotective effect of ranolazine in nondiabetic and diabetic male rats subjected to isoprenaline-induced acute myocardial infarction involves modulation of AMPK and inhibition of apoptosis. Can J Physiol Pharmacol. 97(7), 661–674. doi: 10.1139/cjpp-2018-0571 (2019). La Padula, P.H., Etchegoyen, M., Czerniczyniec, A., Piotrkowski, B., Arnaiz, S.L., Milei, J. & Costa, L.E. Cardioprotection after acute exposure to simulated high altitude in rats. Role of nitric oxide. Nitric Oxide. 73, 52–9. doi: 10.1016/j.niox.2017.12.007 (2018). Kanno S, Lee PC, Zhang Y, Ho C, Griffith BP, Shears LL, Billiar TR. Attenuation of myocardial ischemia/reperfusion injury by superinduction of inducible nitric oxide synthase. Circulation. 101(23), 2742–8. doi: 10.1161/01.cir.101.23.2742 (2000) Katakam, P.V., Ujhelyi, M.R., Hoenig, M. & Miller, A.W. Metformin improves vascular function in insulin-resistant rats. Hypertension. 35(1), 108–12. doi: 10.1161/01.hyp.35.1.108 (2000) Murry, C.E., Jennings, R.B. & Reimer, K.A. Preconditioning with ischemia: a delay of lethal cell injury in ischemic myocardium. Circulation. 74(5), 1124–36. doi: 10.1161/01.cir.74.5.1124 (1986) Napoli, C. New-onset angina preceding acute myocardial infarction is associated with improved contractile recovery after thrombolysis. Eur Heart J. 19(3), 411–9. doi: 10.1053/euhj.1997.0748 (1998). Liu, G.S, Thornton, J., Van Winkle, D.M., Stanley, A.W., Olsson, R.A. & Downey, J.M. Protection against infarction afforded by preconditioning is mediated by A1 adenosine receptors in rabbit heart. Circulation. 84(1), 350–6 doi: 10.1161/01.cir.84.1.350 (1991). Le, D.E., Davis, C.M., Wei, K., Zhao, Y., Cao, Z., Nugent, M., Scott, K.L., Liu, L., Nagarajan, S., Alkayed, N.J. & Kaul, S. Ranolazine may exert its beneficial effects by increasing myocardial adenosine levels. American Journal of Physiology-Heart and Circulatory Physiology. 318(1), H189-202. doi: 10.1152/ajpheart.00217.2019 (2020). Fan, H., Sun, B., Gu, Q., Lafond-Walker, A., Cao, S. & Becker, L.C. Oxygen radicals trigger activation of NF-κB and AP-1 and upregulation of ICAM-1 in reperfused canine heart. Am J Physiol Circ Physiol. 282(5), H1778–86. doi: 10.1152/ajpheart.00796.2000 (2002). Starkopf, J., Bugge, E. & Ytrehus, K. Preischaemic bradykinin and ischaemic preconditioning in functional recovery of the globally ischaemic rat heart. Cardiovasc Res. 33(1), 63–70. doi: 10.1016/s0008-6363(96)00195-2 (1997). Pan, H.L., Chen, S.R., Scicli, G.M. & Carretero, O.A. Cardiac interstitial bradykinin release during ischemia is enhanced by ischemic preconditioning. Am J Physiol Circ Physiol. 279(1), H116–21. doi: 10.1152/ajpheart.2000.279.1.H116 (2000) Wall, T.M., Sheehy, R. & Hartman, J.C. Role of bradykinin in myocardial preconditioning. J Pharmacol Exp Ther. 270(2), 681–9. PMID: 8071859 (1994). Sheng, Z., Yao, Y., Li, Y., Yan, F., Huang, J. & Ma, G. Bradykinin preconditioning improves therapeutic potential of human endothelial progenitor cells in infarcted myocardium. PLoS One. 8(12), e81505. doi: 10.1371/journal.pone.0081505 (2013) Przyklenk, K., Bauer, B., Ovize, M., Kloner, R.A. & Whittaker P. Regional ischemic’preconditioning’protects remote virgin myocardium from subsequent sustained coronary occlusion. Circulation. 87(3), 893–9. doi: 10.1161/01.cir.87.3.893 (1993) Regoli, D. & Barabe, J. Pharmacology of bradykinin and related kinins. Pharmacol Rev. 32(1), 1–46. PMID: 7015371. (1980) Carretero, O.A., Miyazaki, S. & Scicli, A.G. Role of kinins in the acute antihypertensive effect of the converting enzyme inhibitor, captopril. Hypertension. 3(1), 18–22. doi: 10.1161/01.hyp.3.1.18 (1981) Clark, B., Wyatt, K.M. & Mccormack, J.G. Ranolazine increases active pyruvate dehydrogenase in perfused normoxic rat hearts: evidence for an indirect mechanism. J. Mol. Cell Cardiol. 28(2), 341–350. doi: 10.1006/jmcc.1996.0032 (1996). Hanley, P.J., Mickel, M., Löffler, M., Brandt, U. & Daut J. KATP channel-independent targets of diazoxide and 5‐hydroxydecanoate in the heart. J Physiol. 542(Pt 3), 735–41. doi: 10.1113/jphysiol.2002.023960 (2002).. Gross, G.J. & Auchampach, J.A. Blockade of ATP-sensitive potassium channels prevents myocardial preconditioning in dogs. Circulation Research. 70(2), 223–33. doi: 10.1161/01.res.70.2.223 (1992) Ali, K., Morimoto, M., Fukaya, Y. & Furukawa, Y. Improvement of cardiac function impaired by repeated ischemic arrests in isolated rat hearts. The Annals of Thoracic Surgery. 55(4), 902–7. doi: 10.1016/0003-4975(93)90114-w (1993). Olders, J., Turek, Z., Evers, J., Hoofd, L., Oeseburg, B. & Kreuzer, F. Comparison of Tyrode and blood perfused working isolated rat hearts. Adv Exp Med Biol. 277, 403–13. doi: 10.1007/978-1-4684-8181-5_46 (1990). Gettes, L.S. What are the effects of potassium on the electrophysiology of acute ischemia. Life-Threatening Arrhythmias During Ischemia and Infarction. New York, NY: Raven Press Publishers. 77–90. (1987). Curtis, M.J., Macleod, B.A. & Walker, M.J. Models for the study of arrhythmias in myocardial ischaemia and infarction: the use of the rat. Journal of Molecular and Cellular Cardiology. 19(4), 399–419. doi: 10.1016/s0022-2828(87)80585-0 (1987) Schaper, W., Binz, K., Sass, S. & Winkler, B. Influence of collateral blood flow and of variations in MVO2 on tissue-ATP content in ischemic and infarcted myocardium. Journal of Molecular and Cellular Cardiology. 19(1), 19–37. doi: 10.1016/s0022-2828(87)80542-4 (1987). Carmeliet E. Oral antidiabetics and hypoxic shortening of the cardiac action potential. Eur Heart J. 8(Suppl 2), 315 – 27. (1987). Amani, M., Jeddi, S., Ahmadiasl, N., Usefzade, N. & Zaman J. Effect of HEMADO on Level of CK-MB and LDH Enzymes after Ischemia/Reperfusion Injury in Isolated Rat Heart. Bioimpacts. 3(2), 101–4. doi: 10.5681/bi.2013.003 (2013) Additional Declarations No competing interests reported. Supplementary Files Combined.xlsx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3825042","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":267154931,"identity":"fa08ec87-8930-4e8d-a650-5f75b1087136","order_by":0,"name":"Junaid Tantray","email":"","orcid":"","institution":"NIMS Institute of Pharmacy, NIMS University Rajasthan","correspondingAuthor":false,"prefix":"","firstName":"Junaid","middleName":"","lastName":"Tantray","suffix":""},{"id":267154932,"identity":"cbbbf9f8-7eac-43d4-adb6-d73ed0910a61","order_by":1,"name":"Ashish Kumar Sharma","email":"data:image/png;base64,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","orcid":"","institution":"NIMS Institute of Pharmacy, NIMS University Rajasthan","correspondingAuthor":true,"prefix":"","firstName":"Ashish","middleName":"Kumar","lastName":"Sharma","suffix":""},{"id":267154933,"identity":"51a09f9c-e5bb-4565-9c21-d59602d86e80","order_by":2,"name":"Shivam Singh","email":"","orcid":"","institution":"NIMS Institute of Pharmacy, NIMS University Rajasthan","correspondingAuthor":false,"prefix":"","firstName":"Shivam","middleName":"","lastName":"Singh","suffix":""},{"id":267154934,"identity":"df4bd77a-bca9-43f3-9372-7fef25041a92","order_by":3,"name":"Mohammad Zaid","email":"","orcid":"","institution":"NIMS Institute of Pharmacy, NIMS University Rajasthan","correspondingAuthor":false,"prefix":"","firstName":"Mohammad","middleName":"","lastName":"Zaid","suffix":""},{"id":267154935,"identity":"d39b952d-9114-4b7e-bf46-e0c4e035fe3c","order_by":4,"name":"Mehvish Bhat","email":"","orcid":"","institution":"NIMS Institute of Pharmacy, NIMS University Rajasthan","correspondingAuthor":false,"prefix":"","firstName":"Mehvish","middleName":"","lastName":"Bhat","suffix":""},{"id":267154936,"identity":"de05f6df-cbb7-401e-bd09-8d1c7574c72b","order_by":5,"name":"Kartik Gill","email":"","orcid":"","institution":"NIMS Institute of Pharmacy, NIMS University Rajasthan","correspondingAuthor":false,"prefix":"","firstName":"Kartik","middleName":"","lastName":"Gill","suffix":""},{"id":267154937,"identity":"69638a15-8ae2-4629-91b7-221a0b212449","order_by":6,"name":"Rajesh Kumar Sharma","email":"","orcid":"","institution":"NIMS Institute of Pharmacy, NIMS University Rajasthan","correspondingAuthor":false,"prefix":"","firstName":"Rajesh","middleName":"Kumar","lastName":"Sharma","suffix":""},{"id":267154938,"identity":"456eb1cb-fc42-4b43-97e5-e20bab680044","order_by":7,"name":"Ravindra Pal Singh","email":"","orcid":"","institution":"NIMS Institute of Pharmacy, NIMS University Rajasthan","correspondingAuthor":false,"prefix":"","firstName":"Ravindra","middleName":"Pal","lastName":"Singh","suffix":""}],"badges":[],"createdAt":"2023-12-31 02:44:07","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3825042/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3825042/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":49760741,"identity":"883c26e7-7e8f-414c-b4a0-12357cd0ba89","added_by":"auto","created_at":"2024-01-17 15:52:18","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":860090,"visible":true,"origin":"","legend":"\u003cp\u003eVITROUS 5600 Instrument\u003c/p\u003e\n\u003cp\u003eSample loading and CK-MB, LDH estimation machine (VITROUS 5600)\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3825042/v1/391a9db1f7965a47ea652edd.png"},{"id":49760743,"identity":"8d3be891-e521-4e07-bc82-7a0870178a33","added_by":"auto","created_at":"2024-01-17 15:52:18","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":58787,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eInfarct size of rat’s heart\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInfarct size of rat’s heart:\u003c/strong\u003e Values are Mean± SEM of five experiments, (n=6). Here P\u0026gt;0.05 denotes non-significant value, *p≤0.05 denotes significant value, **P\u0026lt;0.01 denotes very significant value, ***P\u0026lt;0.001 denotes extremely significant value. a-indicates comparison between Group I (Control-ischeamia-reperfusion) \u0026amp; Group II(ischeamic preconditioning)(P\u0026lt;0.05), b-indicates comparison between Group I(Control-ischeamia-reperfusion) \u0026amp; Group III(Ranolazine)(P\u0026lt;0.05), c indicates comparison between Group IV(Ranolazine+L-NAME) vs Group III(Ranolazine)(P\u0026lt;0.05), d indicates comparison between Group V(Ranolazine+Aminoguanidine) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). e-indicates comparison between Group VI(Ranolazine+Theophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), f-indicates comparison between Group VII(Ranolazine+Aminophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), g indicates comparison between Group VIII(Enalapril) vs Group III(Ranolazine) (P\u0026lt;0.05), h indicates comparison between Group IX(Ranolazine+Losartan) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). i-indicates comparison between Group X(Ranolazine+5-Hydroxy Decanoate) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), j-indicates comparison between Group XI(Ranolazine+Glimepiride) \u0026amp; Group III(Ranolazine)(P\u0026lt;0.05).\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3825042/v1/62eda1ecfd918e80b5154536.png"},{"id":49760742,"identity":"1fae815e-6eb0-4ce9-9530-ae314c2615af","added_by":"auto","created_at":"2024-01-17 15:52:18","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":51606,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eLactate dehydrogenase (LDH) release in coronary effluent of isolated rat heart at 40 minute reperfusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLactate dehydrogenase (LDH) release in coronary effluent of isolated rat heart at 40 minute reperfusion:\u003c/strong\u003e Values are Mean± SEM of five experiments, (n=6). Here P\u0026gt;0.05 denotes non-significant value, *p≤0.05 denotes significant value, **P\u0026lt;0.01 denotes very significant value, ***P\u0026lt;0.001 denotes extremely significant value. a-indicates comparison between Group I (Control-ischeamia-reperfusion) \u0026amp; Group II(ischeamic preconditioning)(P\u0026lt;0.05), b-indicates comparison between Group I(Control-ischeamia-reperfusion) \u0026amp; Group III(Ranolazine)(P\u0026lt;0.05), c indicates comparison between Group IV(Ranolazine+L-NAME) vs Group III(Ranolazine)(P\u0026lt;0.05), d indicates comparison between Group V(Ranolazine+Aminoguanidine) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). e-indicates comparison between Group VI(Ranolazine+Theophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), f-indicates comparison between Group VII(Ranolazine+Aminophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), g indicates comparison between Group VIII(Enalapril) vs Group III(Ranolazine) (P\u0026lt;0.05), h indicates comparison between Group IX(Ranolazine+Losartan) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). i-indicates comparison between Group X(Ranolazine+5-Hydroxy Decanoate) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), j-indicates comparison between Group XI(Ranolazine+Glimepiride) \u0026amp; Group III(Ranolazine)(P\u0026lt;0.05).\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-3825042/v1/af6394a6a896551d13e78fa8.png"},{"id":49760290,"identity":"49edab0e-9d1a-4329-90d3-7c783be062c0","added_by":"auto","created_at":"2024-01-17 15:44:18","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":45925,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCreatine kinase myoglobin binding (CK-MB) release in coronary effluent of isolated rat heart at 40 minute reperfusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCreatine kinase myoglobin binding (CK-MB) release in coronary effluent of isolated rat heart at 40 minute reperfusion:\u003c/strong\u003e Values are Mean± SEM of five experiments, (n=6). Here P\u0026gt;0.05 denotes non-significant value, *p≤0.05 denotes significant value, **P\u0026lt;0.01 denotes very significant value, ***P\u0026lt;0.001 denotes extremely significant value. a-indicates comparison between Group I (Control-ischeamia-reperfusion) \u0026amp; Group II(ischeamic preconditioning)(P\u0026lt;0.05), b-indicates comparison between Group I(Control-ischeamia-reperfusion) \u0026amp; Group III(Ranolazine)(P\u0026lt;0.05), c indicates comparison between Group IV(Ranolazine+L-NAME) vs Group III(Ranolazine)(P\u0026lt;0.05), d indicates comparison between Group V(Ranolazine+Aminoguanidine) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). e-indicates comparison between Group VI(Ranolazine+Theophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), f-indicates comparison between Group VII(Ranolazine+Aminophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), g indicates comparison between Group VIII(Enalapril) vs Group III(Ranolazine) (P\u0026lt;0.05), h indicates comparison between Group IX(Ranolazine+Losartan) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). i-indicates comparison between Group X(Ranolazine+5-Hydroxy Decanoate) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), j-indicates comparison between Group XI(Ranolazine+Glimepiride) \u0026amp; Group III(Ranolazine)(P\u0026lt;0.05).\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-3825042/v1/676d1428b83183d236a8d1c0.png"},{"id":49760295,"identity":"472b0167-19a6-4c2d-b6a1-3cb39509578d","added_by":"auto","created_at":"2024-01-17 15:44:18","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":195547,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eScheme for the pathophysiology of myocardial ischemia and the role of late I\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003eNa\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003eL inhibition with ranolazine\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-3825042/v1/4d469f257a59eedceba6bdf7.png"},{"id":49760292,"identity":"8f319da3-c59e-4470-8ca6-03d984dfb2fb","added_by":"auto","created_at":"2024-01-17 15:44:18","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":41895,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eLate I\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003eNa\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e under normal and increased late I\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003eNa\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e under pathophysiological conditions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-3825042/v1/7c0fddc32901de0255dcd1e9.png"},{"id":49760744,"identity":"b615b905-be07-427a-af12-bda0f48f2495","added_by":"auto","created_at":"2024-01-17 15:52:18","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":375919,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eIllustration of Ischemic preconditioning\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-3825042/v1/808d1217b0ab9d3d79e2f9d7.png"},{"id":50240497,"identity":"25405801-b05d-4f80-a89e-3c098e0a2848","added_by":"auto","created_at":"2024-01-27 06:52:20","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2658437,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3825042/v1/8bd31c03-1815-4b24-a7ce-2b11243b4b83.pdf"},{"id":49760288,"identity":"d0e971df-bb7b-4f42-a78f-a645c02dc66a","added_by":"auto","created_at":"2024-01-17 15:44:18","extension":"xlsx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":19311,"visible":true,"origin":"","legend":"","description":"","filename":"Combined.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-3825042/v1/a0d2d81235765c7a933829f0.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eRanolazine Exert its Beneficial Effects in myocardial infarction like Ischemic preconditioning mediators by Increasing Myocardial Nitric oxide, Adenosine, Bradykinin and K\u003csup\u003e+\u003c/sup\u003eATPase Levels\u003c/p\u003e","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eAccording to estimates, 17.5\u0026nbsp;million people die from cardiovascular diseases each year, accounting for one-third of all deaths globally (World Health Organization, 2016). Major developments in cardiovascular sciences have occurred during the past century, ranging from non-invasive to interventional techniques like coronary artery bypass graft surgery (CABG) and heart transplantation. Cardiovascular diseases remain the leading cause of morbidity and mortality worldwide despite all the progress. The financial strain on the health care system is enormous as a result. The preferred method of treating acute coronary syndrome (ACS) is myocardial reperfusion; however, sudden restoration of blood flow exacerbates tissue damage brought on by ischemia, a condition known as ischemia/reperfusion injury (IRI). Reperfusion-induced imbalance between chemicals that are vasodilators and vasoconstriction is one of the theories put up to explain this phenomenon [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe investigation of a brand-new cardio protection concept has been sparked by efforts to develop ways to prevent and treat this injury. The prevention of permanent myocardial injury and the protection of ventricular dysfunction, which results in heart failure, are the current hot topics of research and discussion. The term \"cardio protection\" generally refers to all procedures and techniques that lessen or even stop myocardial deterioration and so help to preserve the heart [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eUnfortunately, the majority of animal studies, findings could not be replicated in human settings, possibly as a result of fundamental variations in the risk factors and comorbidities involved [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eNumerous research conducted in the last few decades have revealed that the cardiac cells have a number of defense mechanisms to lessen the harm caused by ischemia/reperfusion. These activities provide protection both in the acute phase following ACS and lessen the long-term effects of myocardial infarction since they are not restricted to the myocardium but are also activated at locations both near and far from the heart (MI). Pre-conditioning and post-conditioning are two examples of myocardial cell protection from ischemia/reperfusion occurrences. The cellular mechanisms underlying these phenomena are still unclear, although they are likely to be complex and may involve components from outside the heart [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWhen first-line antianginal treatments are ineffective at controlling angina symptoms in symptomatic patients, ranolazine is used as an adjunctive treatment. Ranolazine blocks sodium voltage-dependent channels, indicating that the reperfusion process may involve these channels by avoiding the excess salt and calcium that develops during ischemia. In this work, isolated albino Wistar rats were treated to a simulated ischemia and reperfusion regimen in order to assess the effect of ranolazine on cardio protection [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe FDA (Food and Drug Administration) initially authorized ranolazine, a piperazine derivative with a unique mechanism of action, in 2006 for the symptomatic management of patients with chronic angina. Its pharmacological characteristics allow it to make the heart's usage of oxygen more effective by blocking the late Na\u0026thinsp;+\u0026thinsp;current (INaL) in cardiomyocytes and shifting fatty acid oxidation towards glucose oxidation [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Ranolazine's exact mode of action, however, is not yet fully understood. Ranolazine's therapeutic effects come from its ability to inhibit the Na\u0026thinsp;+\u0026thinsp;influx into cardiac cells through Na\u0026thinsp;+\u0026thinsp;channels, which in pathologic conditions either fail to close after being inactivated [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Additionally, it has been proposed that ranolazine could lessen calcium buildup in cardiac cells during ischemia by blocking the I\u003csub\u003eNa\u003c/sub\u003eL current [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIt is clearly demonstrated clinically that ranolozine and ischeamic precondioning produce cardioprotection. Our research question is whether or not ranolazine induce cardioprotection mimicked are same like ischeamic precondioning mediators. If this research hypothesis is proved, ranolazine as a drug replace clinical surgical procedure of ischemic preconditioning before interventional techniques like coronary artery bypass graft surgery (CABG) and heart transplantation.\u003c/p\u003e"},{"header":"2. Material and Methods","content":"\u003cp\u003e\u003cstrong\u003e2.1 Animals:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWistar Albino Rats used in this study were obtained from Animal House, NIMS University Rajasthan, Jaipur. Wistar Albino Rats (125-150 grams, either sex) were employed in the current study. The rats were given unrestricted access to tap water as well as typical laboratory rat diet. The experimental research protocol has been Ethically approved by the Institutional Animal Ethics Committee (IAEC, 2022) [Protocal No. 01, 02, 03, 05, \u0026amp; 08], NIMS University Rajasthan, Jaipur, Rajasthan, India, Registration No. 1203/PO/Re/S/09/CPCSEA, under the supervision of CPCSEA, Government of India, New Delhi, India.\u003c/p\u003e\n\u003cp\u003e- I confirm that all methods were carried out in accordance with relevant guidelines and regulations (Government of India Guidelines- Ministry of Fisheries, Animal Husbandry and Dairying, C/o Committee for purpose of Control and Supervision of Experiments on Animals [CPCSEA]) .\u003c/p\u003e\n\u003cp\u003e- I confirm that all methods are reported in accordance with ARRIVE guidelines (https://arriveguidelines.org).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2 Drugs \u0026amp; Chemicals\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe drugs and chemicals which are used during experimental procedure are mentioned below (Table 1):\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 1: Drugs \u0026amp; Chemicals and their Procurement\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003eS.NO.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eDrug Name\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eProcurement\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e1.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eRanolazine\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eGlenmark Pharmaceuticals Limited, Maharashtra.\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e2.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eKetamine\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eTroika Pharmaceuticals Limited, Uttarakhand, India.\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e3\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eL-NAME\u0026nbsp;(N\u003csup\u003eώ\u003c/sup\u003e-nitro-L-arginine methyl ester)\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eTokyo Chemical Industry Co. Ltd., Toshima, Kita-Ku., Tokya, Japan\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e4.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eAminoguanidine\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;BLD Pharmatech (India) Pvt. Ltd., Hyderabad. 501401, Telangana, INDIA\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e5.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eTheophylline\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eZydus Healthcare Limited, Hyderabad India\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e6.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eAminophylline\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eRathi Laboratories, Patna, India.\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e7.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eEnalapril Maleate\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eBATCH NO. EMI-1118054, VENDOR: NEULAND LABORATORIES LTD. R\u0026amp;D, Medley Pharmaceuticals Ltd., Mumbai, India\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e8.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eLOSARTAN POTASSIUM USP (1000272)\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eBATCH NO. 1943109612, VENDOR: VASUDHA PHARMA CHEM LIMITED R\u0026amp;D, Medley Pharmaceuticals Ltd., Mumbai, India\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e9.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003e5-Hydroxydeconate\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eBLD Pharmatech Limited, Telegana, India\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e10.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eGlimepride\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eMedely Pharmaceuticals Ltd. Mumbai. India\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e11.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eHeparin\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eBE Pharmaceuticals Private Limited, Telangana India.\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e12.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eTriphenyl tetrazolium Chloride\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eBLD Pharmatech (India) Private Limited, Telangana India.\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e13.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eNaHCO\u003csub\u003e3\u003c/sub\u003e, NaH\u003csub\u003e2\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eQualikems Fine Chem Private Limited, Vadodara India\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e14.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eMgSO\u003csub\u003e4\u003c/sub\u003e, CaCl\u003csub\u003e2\u003c/sub\u003e, Diethyl ether,\u003cbr\u003eCarboxymethylcellulose\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eCentral Drug Store (P) Limited. Ne Indiaw Delhi\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e15.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eKCl, Dextrose, NaCl\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eAses Chemicals, Jodhpur, India.\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.423550087873462%\" valign=\"top\"\u003e16.\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.434094903339194%\" valign=\"top\"\u003eNa\u003csub\u003e2\u003c/sub\u003eHPO\u003csub\u003e4\u003c/sub\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"51.14235500878735%\" valign=\"top\"\u003eRFCL Limited, New Delhi. India\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e2.3 Biomarkers-LDH, CK-MB [12]\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMyocardial infarction leads to an increase in the serum isoenzyme of myocardial-associated creatine kinase (CK-MB) and the isoenzyme serum lactate dehydrogenase (LDH). Because the atrial myocardium contains the same amount of CK-MB as the ventricular myocardium, surgical manipulation of the atrium in the postoperative period can result in elevated serum CK-MB levels [11].\u003c/p\u003e\n\u003cp\u003eThe distribution of the LDH isoenzymes is different in the myocardium of the atria and ventricles. Elevated serum enzymes due to myocardial necrosis are considered a specific finding of myocardial infarction. The aim of this study was to determine the changes in the concentrations of LDH, CK-MB isoenzymes in animals after coronary artery bypass graft implantation and after atriotomy for surgical correction without symptoms of myocardial infarction who have been diagnosed on the basis of clinical studies, hemodynamic and electrocardiographic results. CK-MB, LDH, show significant elevations resembling perioperative myocardial infarction [12].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.4 Infarct Size Measurement\u003c/strong\u003e \u003cstrong\u003e[13]\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInfract size measurement was carried by two methods\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003eBy volume method\u003c/li\u003e\n \u003cli\u003eBy weight method\u0026nbsp;\u003c/li\u003e\n\u003c/ol\u003e\n\u003cul\u003e\n \u003cli\u003eBy volume method\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThe slices\u0026nbsp;were placed between two glass plates. A transparent plastic grid with 100 squares of 1 cm\u003csup\u003e2\u003c/sup\u003e was placed on top. The mean area of each slice was calculated by counting the number of squares on either side. Likewise, the number of squares falling on the yellow part was also counted. The infarct surface was expressed as a percentage of the total surface [13].\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eBy weight method\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eAll slices were weighed. The yellow infarct portion was removed and weighed. Infarct size was expressed as a percentage of total weight.\u003c/p\u003e\n\u003cp\u003eBy the two mentioned methods percentage infarction in hearts of five groups have been measured[13].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.5 Surgical preparations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eApparatus- Langendorff\u0026apos;s apparatus (INCO, Ambala, India), ECG (BPL CARDIAART 108TDIGI, New Delhi, India)\u003c/p\u003e\n\u003cp\u003eThe Langendorff cardiac test, or isolated perfused cardiac test, is an ex vivo technique used in pharmacological and physiological studies in animals and humans. This technique, named after the German physiologist Oskar Langendorff, allows the study of cardiac muscle contractile force and heart rate without the complications encountered in intact animals or humans [14].\u003c/p\u003e\n\u003cp\u003eIn the Langendorff preparation, the heart is removed from the animal or human body by severing the blood vessels. This is followed by reverse perfusion (retrograde perfusion) through the aorta, usually with a nutrient-rich oxygen-containing solution\u003c/p\u003e\n\u003cp\u003e( Krebs-Henseleit solution)[13].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.6 Procedure[13]\u003c/strong\u003e\u003c/p\u003e\n\u003cul class=\"decimal_type\"\u003e\n \u003cli\u003eRats anaesthetized with ketamine 100mg/kg Limb lead II ECG installed and rat chest was opened.\u003c/li\u003e\n \u003cli\u003eHeparin (500 IU, i.p.) was administered just under 15 minutes before animal sacrificed.\u003c/li\u003e\n \u003cli\u003eHeart was exposed and pericardium was removed. The heart was quickly removed and was immediately mounted on the Langendorff apparatus.\u003c/li\u003e\n \u003cli\u003eThe aorta was retrogradely perfused under constant pressure70 mmHg with Krebs-Henseleit buffer (118 mM NaCl; KCl 4.7 mM; CaCl\u003csub\u003e2\u003c/sub\u003e 2.5 mM; MgSO\u003csub\u003e4\u003c/sub\u003e.7H\u003csub\u003e2\u003c/sub\u003eO 1.2 mM ; NaHCO\u003csub\u003e3\u003c/sub\u003e 25 mM; KH\u003csub\u003e2\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e 1.2 mM; C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e12\u003c/sub\u003eO\u003csub\u003e6\u003c/sub\u003e 11 mM) was retrogradely perfused into the aorta under continuous pressure of 70mmHg while bubbling with 95% O\u003csub\u003e2\u003c/sub\u003e and 5% CO\u003csub\u003e2\u003c/sub\u003e.\u003c/li\u003e\n \u003cli\u003eThe heart was surrounded by a double-walled coat, whose temperature was maintained by circulation water was heated to 37\u0026deg;C Ischemia ensued 20-minute respected by reperfusion for 40 minutes.\u003c/li\u003e\n \u003cli\u003eElectrocardiography (ECG) (GLP-CARDIAART 108T-DIGI, New Delhi, India) was made using two silver electrodes attached to the apex of the left ventricle and apex of right auricle. ECG recording immediately after stabilization, 0, 10 and 20-minutes during ischemia and immediately, 0, 10,20, 30 and 40 minutes after reperfusion.\u003c/li\u003e\n \u003cli\u003eLeft anterior descending coronary artery was ligated for 20 min ischemia by passing 4/0 silken thread and is being tied by shoelace knot.\u003c/li\u003e\n \u003cli\u003eAfter 20 min of ischemia 40min of reperfusion was done. The above is the protocol of ischemia reperfusion injury.\u003c/li\u003e\n \u003cli\u003eCoronary effusion was collected at the end of reperfusion for the determination of lactate dehydrogenase (LDH) \u0026amp; CK-MB.\u003c/li\u003e\n \u003cli\u003eAfter ischemia reperfusion injury heart was excised, aorta and auricles removed and heart was frozen in deep freeze.\u003c/li\u003e\n \u003cli\u003eAfter 24hrs heart was removed from freezer and 1mm thickness slices of heart was made. Then stained with TTC (Triphenyl tetrazolium chloride) and Evan\u0026rsquo;s Blue at 37\u0026ordm;C in incubator.\u003c/li\u003e\n \u003cli\u003eAfter 10min stained slices has been washed with saline and placed in between two glass plates.\u003c/li\u003e\n \u003cli\u003e\u0026nbsp;Graph transparency was put on the glass plate and infarct size was calculated by volume method and after that, infarct size was calculated by weight method. The pre-treatment of drugs before ischemia reperfusion injury model was done to elucidate mechanism of action of drugs.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003e2.7 Experimental protocol (Table 2)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere were 30 wistar albino rats utilized in this investigation, divided into six groups with an average of six animals per group (n=6).\u003c/p\u003e\n\u003cp\u003eTable 2: Different type of groups with number of animals\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eS.NO\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eGROUP\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003eNO. of Animals\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eI\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eControl (Ischeamia-reperfusion)\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003en=6\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eII\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eIscheamic preconditioning\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003en=6\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eIII\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eRanolazine\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003en=6\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eIV\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eRanolazine and L-NAME\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003en=6\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eV\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eRanolazine and Aminoguanidine\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003en=6\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eVI\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eRanolazine and Theoplylline\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003en=6\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eVII\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eRanolazine and Aminoplylline\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003en=6\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eVII\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eRanolazine and Enalapril\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003en=6\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eIX\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eRanolazine and Losartan\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003en=6\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eX\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eRanolazine and 5-hydroxydecanoate\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003en=6\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.455516014234876%\" valign=\"top\"\u003eXI\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eRanolazine and Glimepiride\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"37.544483985765126%\" valign=\"top\"\u003en=6\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eGroup I: The control group (ischemia-reperfusion)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirst the rat has been anaesthetized with ketamine 100mg/kg, Limblead II ECG installed \u0026amp; Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup II: Group for ischemic preconditioning\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBefore ischemia-reperfusion, heart underwent an ischemic preconditioning programme. First the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed \u0026amp; Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup III: Pre-treatment of Ranolazine drug\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirst the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed \u0026amp; Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100\u0026micro;mol/L) were added in Physiological salt solution (PSS) earlier.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup IV: Ranolazine and L-NAME\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirst the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed \u0026amp; Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100\u0026micro;mol/L) and L-NAME drug (30\u0026micro;mol/L) were added in Physiological salt solution (PSS) earlier.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup V: Ranolazine and Aminoguanidine\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirst the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed \u0026amp; Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100\u0026micro;mol/L) and Aminoguanidine(30\u0026micro;mol/L) \u0026nbsp;drug were added in Physiological salt solution (PSS) earlier.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup VI: Ranolazine and Theophylline\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirst the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed \u0026amp; Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100\u0026micro;mol/L) and Theophylline drug (50\u0026micro;mol/L) were added in Physiological salt solution (PSS) earlier.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup VII: Ranolazine and Aminophylline\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirst the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed \u0026amp; Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100\u0026micro;mol/L) and Aminophylline(50\u0026micro;mol/L) \u0026nbsp;drug were added in Physiological salt solution (PSS) earlier.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup VIII: Ranolazine and Enalapril\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirst the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed \u0026amp; Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100\u0026micro;mol/L) and Enalapril drug (100\u0026micro;mol/L) were added in Physiological salt solution (PSS) earlier.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup IX: Ranolazine and Losartan\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirst the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed \u0026amp; Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100\u0026micro;mol/L) and Losartan(50\u0026micro;mol/L) \u0026nbsp;drug were added in Physiological salt solution (PSS) earlier.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup X: Ranolazine and 5-Hydroxydecanoate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirst the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed \u0026amp; Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100\u0026micro;mol/L) and 5-Hydroxydecanoate drug (30\u0026micro;mol/L) were added in Physiological salt solution (PSS) earlier.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup XI: Ranolazine and Gimepiride\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirst the rat has been anaesthetized with ketamine 100mg/kg, Limb lead II ECG installed \u0026amp; Heparin was given 15min before excision of heart, rat chest was opened, heart exposed and pericardium was removed. Heart was excised and mounted on Langendorff apparatus. Left anterior descending coronary artery was ligate for 20 min ischemia by passing 4/0 siliken thread by tieing shoe lace knot. After 20 min of ischemia 40min of reperfusion was done. Ranolazine(100\u0026micro;mol/L) and Glimepiride(50\u0026micro;mol/L) \u0026nbsp;drug were added in Physiological salt solution (PSS) earlier.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.8 Staining procedure\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe heart was removed from Langendorff\u0026rsquo;s apparatus. It was kept in refrigerator for 24 hours. Then the 1mm slices of frozen heart were made. The slices of heart were stained with TTC (Triphenyl tetrazolium chloride) and Evan\u0026rsquo;s Blue and kept in BOD incubator for 10 minutes. After 10 min the slices were removed from incubator and infract size was measured after washing by saline[13] . \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.9. Estimation of LDH and CK-MB\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.9.1 LDH- Lactate dehydrogenase (LDH) assay (Figure 1)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLDH was measured in coronary fluid using the integrated VITROUS system 5600 apparatus.\u003c/p\u003e\n\u003cp\u003ePrinciple -\u003c/p\u003e\n\u003cp\u003eLDH catalyzes the following reaction: lactate \u0026thorn; NAD $ pyruvate \u0026thorn; NADH:\u003c/p\u003e\n\u003cp\u003eThe pyruvate thus formed is coupled with 2,4-DNPH to the corresponding hydrazone, which gives a brown color in alkaline medium. The intensity of this color is proportional to the amount of LDH activity and is measured spectrophotometrically at 440 nm.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.9.2 Creatine Phosphokinase (CK) Assay (Figure 1)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe creatine phosphokinase (CPK) concentration was determined in the coronary fluid also using the integrated VITROUS system 5600 apparatus.\u003c/p\u003e\n\u003cp\u003ePrinciple-\u003c/p\u003e\n\u003cp\u003eIt catalyzes the following reaction: creatine phosphate \u0026thorn; ADP $ creatine \u0026thorn; ATP: At pH 7.4, CPK catalyzes the forward reaction. The resulting creatine reacts with diacetyl and naphthol in alkaline medium, resulting in a pink color. The intensity of this color is proportional to the enzymatic activity and is measured spectrophotometrically at 520 nm. Mg2+ and cysteine are added as activators. The p-chloromercuric benzoate stops the reaction by inactivating the enzyme [13].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.10 Statistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eValues for enzymatic data and infract size were expressed as Mean \u0026plusmn; standard error of the mean (SEM). Statistical significance was calculated using one-way analysis of variance. Dunnett\u0026rsquo;s test and student\u0026rsquo;s t-test were employed as \u003cem\u003epost hoc\u003c/em\u003e testes for comparision with the control group and multiple comparisions between groups, respectively. A value of \u003cem\u003eP \u0026lt; 0.05\u003c/em\u003e is considered to be statistically significant. SigmaPlot v15 software was used for statistical analysis.\u003c/p\u003e"},{"header":"3. Results","content":"\u003cp\u003e\u003cstrong\u003e3.1 Effect of Control (ischeamia-reperfusion) and ischemic preconditioning group on myocardial infarction, LDH \u0026amp; CK-MB (Figure 2, 3 \u0026amp; 4); (Table 3, 4 \u0026amp; 5)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn ischemic preconditioning group myocardial infarct size decreases significantly as compared to control (ischeamia-reperfusion) group. The myocardial infarction in control group was found to be of 65.667\u0026plusmn;0.558 and myocardial infarction in ischemic preconditioning group was found to be 5.1667\u0026plusmn;0.478. The LDH in control group was found to be of 155.500\u0026plusmn;0.958and LDH in ischemic preconditioning group was found to be 101.667\u0026plusmn;2.789. The CK-MB in control group was found to be of 198.500\u0026plusmn;1.803 and CK-MB in ischemic preconditioning group was found to be 97.167\u0026plusmn;1.721.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2 Effect of Control (ischeamia-reperfusion) and Ranolazine treatment group on myocardial infarction, LDH \u0026amp; CK-MB (Figure 2, 3 \u0026amp; 4); (Table 3, 4 \u0026amp; 5)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn Ranolazine treatment group myocardial infarct size decreases significantly as compared to control (ischeamia-reperfusion) group.\u0026nbsp;The myocardial infarction in control group was found to be\u0026nbsp;of 65.667\u0026plusmn;0.558\u0026nbsp;and myocardial infarction in Ranolazine treatment group was found to be\u0026nbsp;5.334\u0026plusmn;\u0026nbsp;0.422. The LDH in control group was found to be\u0026nbsp;of 155.500\u0026plusmn;0.958and LDH in ranolazine treatment group was found to be\u0026nbsp;101.500\u0026plusmn;1.147. The CK-MB in control group was found to be\u0026nbsp;of 198.500\u0026plusmn;1.803\u0026nbsp;and CK-MB in ranolazine treatment group was found to be\u0026nbsp;100.167\u0026plusmn;1.302.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3 Effect of Ranolazine and Ranolazine+L-NAME (Nitric oxide synthase inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 \u0026amp; 4); (Table 3, 4 \u0026amp; 5)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eL-NAME being a Nitric oxide synthase inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug. The myocardial infarction in Ranolazine+L-NAME group was found to be\u0026nbsp;of 64.167\u0026plusmn;0.872 and myocardial infarction in Ranolazine treatment group was found to be\u0026nbsp;5.334\u0026plusmn;\u0026nbsp;0.422. The LDH in Ranolazine+L-NAME group was found to be\u0026nbsp;of 154.667\u0026plusmn;1.256\u0026nbsp;and LDH in ranolazine treatment group was found to be\u0026nbsp;101.500\u0026plusmn;1.147. The CK-MB in Ranolazine+L-NAME group was found to be\u0026nbsp;of 200.167\u0026plusmn;1.537\u0026nbsp;and CK-MB in ranolazine treatment group was found to be\u0026nbsp;100.167\u0026plusmn;1.302.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.4 Effect of Ranolazine and Ranolazine+Aminoguanidine (Nitric oxide synthase inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 \u0026amp; 4); (Table 3, 4 \u0026amp; 5)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAminoguanidine being a Nitric oxide synthase inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug. The myocardial infarction in Ranolazine+Aminoguanidine group was found to be\u0026nbsp;of 64.500\u0026plusmn;0.885\u0026nbsp;and myocardial infarction in Ranolazine treatment group was found to be\u0026nbsp;5.334\u0026plusmn;\u0026nbsp;0.422. The LDH in Ranolazine+Aminoguanidine group was found to be\u0026nbsp;of 154.833\u0026plusmn;1.1377and LDH in ranolazine treatment group was found to be\u0026nbsp;101.500\u0026plusmn;1.147. The CK-MB in Ranolazine+Aminoguanidine group was found to be\u0026nbsp;of 198.333\u0026plusmn;1.145and CK-MB in ranolazine treatment group was found to be\u0026nbsp;100.167\u0026plusmn;1.302.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.5 Effect of Ranolazine and Ranolazine+Theophylline (Adenosine inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 \u0026amp; 4); (Table 3, 4 \u0026amp; 5)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTheoplylline being an adenosine inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+Theophylline group was found to be of 64.667\u0026plusmn;0.760 \u0026nbsp;and myocardial infarction in Ranolazine treatment group was found to be 5.334\u0026plusmn; 0.422. The LDH in Ranolazine+Theophylline group was found to be of 155.167\u0026plusmn;1.301 and LDH in ranolazine treatment group was found to be 101.500\u0026plusmn;1.147. The CK-MB in Ranolazine+Theophylline group was found to be of 199.167\u0026plusmn;1.376 and CK-MB in ranolazine treatment group was found to be 100.167\u0026plusmn;1.302.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.6 Effect of Ranolazine and Ranolazine+Aminophylline (Adenosine inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 \u0026amp; 4); (Table 3, 4 \u0026amp; 5)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAminophylline being an adenosine inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+Aminophylline group was found to be\u0026nbsp;of 65.167\u0026plusmn;0.601\u0026nbsp;and myocardial infarction in Ranolazine treatment group was found to be\u0026nbsp;5.334\u0026plusmn;\u0026nbsp;0.422. The LDH in Ranolazine+Aminophylline group was found to be\u0026nbsp;of 155.333\u0026plusmn;0.615\u0026nbsp;and LDH in ranolazine treatment group was found to be\u0026nbsp;101.500\u0026plusmn;1.147. The CK-MB in Ranolazine+Aminophylline group was found to be\u0026nbsp;of 199.500\u0026plusmn;\u0026nbsp;1.765\u0026nbsp;and CK-MB in ranolazine treatment group was found to be\u0026nbsp;100.167\u0026plusmn;1.302.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.7 Effect of Ranolazine and Ranolazine+Enalapril (Bradykinin inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 \u0026amp; 4); (Table 3, 4 \u0026amp; 5)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEnalapril being an bradykinin inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+Enalapril group was found to be\u0026nbsp;of 64.667\u0026plusmn;0.615\u0026nbsp;and myocardial infarction in Ranolazine treatment group was found to be\u0026nbsp;5.334\u0026plusmn;\u0026nbsp;0.422. The LDH in Ranolazine+Enalapril group was found to be\u0026nbsp;of 154.667\u0026plusmn;\u0026nbsp;1.085\u0026nbsp;and LDH in ranolazine treatment group was found to be\u0026nbsp;101.500\u0026plusmn;1.147. The CK-MB in Ranolazine+Enalapril group was found to be\u0026nbsp;of 201.8333\u0026plusmn;1.990\u0026nbsp;and CK-MB in ranolazine treatment group was found to be\u0026nbsp;100.167\u0026plusmn;1.302.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.8 Effect of Ranolazine and Ranolazine+Losartan (Bradykinin inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 \u0026amp; 4); (Table 3, 4 \u0026amp; 5)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLosartan being an bradykinin inhibitor increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+Losartan group was found to be\u0026nbsp;of 63.667\u0026plusmn;1.282\u0026nbsp;and myocardial infarction in Ranolazine treatment group was found to be\u0026nbsp;5.334\u0026plusmn;\u0026nbsp;0.422. The LDH in Ranolazine+Losartan group was found to be\u0026nbsp;of 155.167\u0026plusmn;0.909and LDH in ranolazine treatment group was found to be\u0026nbsp;101.500\u0026plusmn;1.147. The CK-MB in Ranolazine+Losartan group was found to be\u0026nbsp;of 199.500\u0026plusmn;2.349\u0026nbsp;and CK-MB in ranolazine treatment group was found to be\u0026nbsp;100.167\u0026plusmn;1.302.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.9 Effect of Ranolazine and Ranolazine+5-Hydroxydecanoate(K\u003csup\u003e+\u003c/sup\u003eATPase inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 \u0026amp; 4); (Table 3, 4 \u0026amp; 5)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e5-Hydroxydecanoate a K\u003csup\u003e+\u003c/sup\u003eATPase inhibitor,\u0026nbsp;increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+5-Hydroxydecanoate group was found to be\u0026nbsp;of 63.833\u0026plusmn;1.352\u0026nbsp;and myocardial infarction in Ranolazine treatment group was found to be\u0026nbsp;5.334\u0026plusmn;\u0026nbsp;0.422. The LDH in Ranolazine+5-Hydroxydecanoate group was found to be\u0026nbsp;of 154.667\u0026plusmn;1.054\u0026nbsp;and LDH in ranolazine treatment group was found to be\u0026nbsp;101.500\u0026plusmn;1.147. The CK-MB in Ranolazine+5-Hydroxydecanoate group was found to be\u0026nbsp;of 201.833\u0026plusmn;1.815\u0026nbsp;and CK-MB in ranolazine treatment group was found to be\u0026nbsp;100.167\u0026plusmn;1.302.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.10 Effect of Ranolazine and Ranolazine+Glimepiride(K\u003csup\u003e+\u003c/sup\u003eATPase inhibitor) on myocardial infarction, LDH and CK-MB. (Figure 2, 3 \u0026amp; 4); (Table 3, 4 \u0026amp; 5)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGlimepiride a K\u003csup\u003e+\u003c/sup\u003eATPase inhibitor,\u0026nbsp;increases the myocardial infarct size when it given in combination with ranolazine drug as compared to treatment with ranolazine drug separately. The myocardial infarction in Ranolazine+Glimepiride group was found to be\u0026nbsp;of 63.667\u0026plusmn;0.989\u0026nbsp;and myocardial infarction in Ranolazine treatment group was found to be\u0026nbsp;5.334\u0026plusmn;\u0026nbsp;0.422. The LDH in Ranolazine+Glimepiride group was found to be\u0026nbsp;of 155.833\u0026plusmn;1.352and LDH in ranolazine treatment group was found to be\u0026nbsp;101.500\u0026plusmn;1.147. The CK-MB in Ranolazine+Glimepiride group was found to be\u0026nbsp;of 199.833\u0026plusmn;1.579\u0026nbsp;and CK-MB in ranolazine treatment group was found to be\u0026nbsp;100.167\u0026plusmn;1.302.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3: Myocardial infarct size of different group of animals\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"559\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eS.No.\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroups\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroups Description\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Infarct Size\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e1.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003eControl(Ischeamia-Reperfusion)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e65.667\u0026plusmn;0.558\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e2.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003eIschemic preconditioning\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e5.1667\u0026plusmn;0.47***a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e3.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eIII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e5.334\u0026plusmn;0.422\u0026nbsp;***b\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e4.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eIV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine+ L-NAME\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e64.167\u0026plusmn;0.872***c\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e5.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine+Aminoguanidine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e64.500\u0026plusmn;0.885 ***d\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eVI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Theoplylline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e64.667\u0026plusmn;0.760***e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eVII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Aminoplylline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e65.167\u0026plusmn;0.601***f\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eVII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Enalapril\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e64.667\u0026plusmn;0.615***g\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eIX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Losartan\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e63.667\u0026plusmn;1.282***h\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and 5-hydroxydecanoate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e63.833\u0026plusmn;1.352***i\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eXI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"47.227191413237925%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Glimepiride\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.906976744186046%\" valign=\"top\"\u003e\n \u003cp\u003e63.667\u0026plusmn;0.989***j\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eInfarct size of rat\u0026rsquo;s heart:\u003c/strong\u003e Values are Mean\u0026plusmn; SEM of five experiments, (n=6). Here P\u0026gt;0.05 denotes non-significant value, *p\u0026le;0.05 denotes significant value, **P\u0026lt;0.01 denotes very significant value, ***P\u0026lt;0.001 denotes extremely significant value. a-indicates comparison between Group I \u0026amp; Group II(P\u0026lt;0.05), b-indicates comparison between Group I \u0026amp; Group III(P\u0026lt;0.05), c indicates comparison between Group IV vs Group III(P\u0026lt;0.05), d indicates comparison between Group V \u0026amp; Group III(P\u0026lt;0.05). e-indicates comparison between Group VI \u0026amp; Group III(P\u0026lt;0.05), f-indicates comparison between Group VII \u0026amp; Group III(P\u0026lt;0.05), g indicates comparison between Group VIII vs Group III(P\u0026lt;0.05), h indicates comparison between Group IX \u0026amp; Group III(P\u0026lt;0.05). i-indicates comparison between Group X \u0026amp; Group III(P\u0026lt;0.05), j-indicates comparison between Group XI \u0026amp; Group III(P\u0026lt;0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInfarct size of rat\u0026rsquo;s heart:\u003c/strong\u003e Values are Mean\u0026plusmn; SEM of five experiments, (n=6). Here P\u0026gt;0.05 denotes non-significant value, *p\u0026le;0.05 denotes significant value, **P\u0026lt;0.01 denotes very significant value, ***P\u0026lt;0.001 denotes extremely significant value. a-indicates comparison between Group I (Control-ischeamia-reperfusion) \u0026amp; Group II(ischeamic preconditioning)(P\u0026lt;0.05), b-indicates comparison between Group I(Control-ischeamia-reperfusion) \u0026nbsp;\u0026amp; Group III(Ranolazine)(P\u0026lt;0.05), c indicates comparison between Group IV(Ranolazine+L-NAME) vs Group III(Ranolazine)(P\u0026lt;0.05), d indicates comparison between Group V(Ranolazine+Aminoguanidine) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). e-indicates comparison between Group VI(Ranolazine+Theophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), f-indicates comparison between Group VII(Ranolazine+Aminophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), g indicates comparison between Group VIII(Enalapril) vs Group III(Ranolazine) (P\u0026lt;0.05), h indicates comparison between Group IX(Ranolazine+Losartan) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). i-indicates comparison between Group X(Ranolazine+5-Hydroxy Decanoate) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), j-indicates comparison between Group XI(Ranolazine+Glimepiride) \u0026amp; Group III(Ranolazine)(P\u0026lt;0.05).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4: Lactate dehydrogenase (LDH) release in coronary effluent of isolated rat heart at 40 minute reperfusion\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"559\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eS.No.\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroups\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroups Description\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eLactate dehydrogenase (LDH) at 40 minute reperfusion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e1.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003eControl(Ischeamia-Reperfusion)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e155.500\u0026plusmn;0.957\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e2.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003eII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003eIschemic preconditioning\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e101.667\u0026plusmn;2.789***a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e3.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003eIII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e101.500\u0026plusmn;1.147***b\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e4.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003eIV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine+ L-NAME\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e154.667\u0026plusmn;1.256***c\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e5.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003eV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine+Aminoguanidine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e154.833\u0026plusmn;1.1377***d\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003eVI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Theoplylline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e155.167\u0026plusmn;1.301708***e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003eVII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Aminoplylline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e155.333\u0026plusmn;0.615***f\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003eVII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Enalapril\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e154.667\u0026plusmn;\u0026nbsp;1.085***g\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003eIX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Losartan\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e155.167\u0026plusmn;\u0026nbsp;0.909***h\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and 5-hydroxydecanoate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e154.667\u0026plusmn;1.054***i\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.806797853309481%\" valign=\"top\"\u003e\n \u003cp\u003eXI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.08050089445438%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Glimepiride\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.2737030411449%\" valign=\"top\"\u003e\n \u003cp\u003e155.833\u0026plusmn;1.352***j\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eLactate dehydrogenase (LDH) release in coronary effluent of isolated rat heart at 40 minute reperfusion:\u003c/strong\u003e Values are Mean\u0026plusmn; SEM of five experiments, (n=6). Here P\u0026gt;0.05 denotes non-significant value, *p\u0026le;0.05 denotes significant value, **P\u0026lt;0.01 denotes very significant value, ***P\u0026lt;0.001 denotes extremely significant value, a-indicates comparison between Group I \u0026amp; Group II, b-indicates comparison between Group I \u0026amp; Group III, c indicates comparison between Group IV vs Group III, d indicates comparison between Group V \u0026amp; Group III. e-indicates comparison between Group VI \u0026amp; Group III, f-indicates comparison between Group VII \u0026amp; Group III, g indicates comparison between Group VIII vs Group III, h indicates comparison between Group IX \u0026amp; Group III. i-indicates comparison between Group X \u0026amp; Group III, j-indicates comparison between Group XI \u0026amp; Group III.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure 3: Lactate dehydrogenase (LDH) release in coronary effluent of isolated rat heart at 40 minute reperfusion\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLactate dehydrogenase (LDH) release in coronary effluent of isolated rat heart at 40 minute reperfusion:\u003c/strong\u003e Values are Mean\u0026plusmn; SEM of five experiments, (n=6). Here P\u0026gt;0.05 denotes non-significant value, *p\u0026le;0.05 denotes significant value, **P\u0026lt;0.01 denotes very significant value, ***P\u0026lt;0.001 denotes extremely significant value. a-indicates comparison between Group I (Control-ischeamia-reperfusion) \u0026amp; Group II(ischeamic preconditioning)(P\u0026lt;0.05), b-indicates comparison between Group I(Control-ischeamia-reperfusion) \u0026nbsp;\u0026amp; Group III(Ranolazine)(P\u0026lt;0.05), c indicates comparison between Group IV(Ranolazine+L-NAME) vs Group III(Ranolazine)(P\u0026lt;0.05), d indicates comparison between Group V(Ranolazine+Aminoguanidine) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). e-indicates comparison between Group VI(Ranolazine+Theophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), f-indicates comparison between Group VII(Ranolazine+Aminophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), g indicates comparison between Group VIII(Enalapril) vs Group III(Ranolazine) (P\u0026lt;0.05), h indicates comparison between Group IX(Ranolazine+Losartan) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). i-indicates comparison between Group X(Ranolazine+5-Hydroxy Decanoate) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), j-indicates comparison between Group XI(Ranolazine+Glimepiride) \u0026amp; Group III(Ranolazine)(P\u0026lt;0.05).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5: Creatine kinase myoglobin binding (CK-MB) release in coronary effluent of isolated rat heart at 40 minute reperfusion.\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"559\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eS.No.\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroups\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroups Description\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eLactate dehydrogenase (LDH) at 40 minute reperfusion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e1.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003eControl(Ischeamia-Reperfusion)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e198.500\u0026plusmn;1.803\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e2.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003eIschemic preconditioning\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e97.167\u0026plusmn;1.721***a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e3.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eIII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e100.167\u0026plusmn;1.302***b\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e4.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eIV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine+ L-NAME\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e200.167\u0026plusmn;1.537***c\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e5.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine+Aminoguanidine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e198.333\u0026plusmn;1.145***d\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eVI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Theoplylline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e199.167\u0026plusmn;1.376***e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eVII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Aminoplylline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e199.500\u0026plusmn;\u0026nbsp;1.765***f\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eVII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Enalapril\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e201.8333\u0026plusmn;1.990***g\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eIX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Losartan\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e199.500\u0026plusmn;2.349***h\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and 5-hydroxydecanoate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e201.833\u0026plusmn;1.815***i\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"9.838998211091234%\" valign=\"top\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.026833631484795%\" valign=\"top\"\u003e\n \u003cp\u003eXI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.71377459749553%\" valign=\"top\"\u003e\n \u003cp\u003eRanolazine and Glimepiride\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.42039355992844%\" valign=\"top\"\u003e\n \u003cp\u003e199.833\u0026plusmn;1.579***j\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eCreatine kinase myoglobin binding (CK-MB) release in coronary effluent of isolated rat heart at 40 minute reperfusion: Values are Mean\u0026plusmn; SEM of five experiments, (n=6). Here P\u0026gt;0.05 denotes non-significant value, *p\u0026le;0.05 denotes significant value, **P\u0026lt;0.01 denotes very significant value, ***P\u0026lt;0.001 denotes extremely significant value, a-indicates comparison between Group I \u0026amp; Group II, b-indicates comparison between Group I \u0026amp; Group III, c indicates comparison between Group IV vs Group III, d indicates comparison between Group V \u0026amp; Group III. e-indicates comparison between Group VI \u0026amp; Group III, f-indicates comparison between Group VII \u0026amp; Group III, g indicates comparison between Group VIII vs Group III, h indicates comparison between Group IX \u0026amp; Group III. i-indicates comparison between Group X \u0026amp; Group III, j-indicates comparison between Group XI \u0026amp; Group III. \u0026nbsp; \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCreatine kinase myoglobin binding (CK-MB) release in coronary effluent of isolated rat heart at 40 minute reperfusion:\u003c/strong\u003e Values are Mean\u0026plusmn; SEM of five experiments, (n=6). Here P\u0026gt;0.05 denotes non-significant value, *p\u0026le;0.05 denotes significant value, **P\u0026lt;0.01 denotes very significant value, ***P\u0026lt;0.001 denotes extremely significant value. a-indicates comparison between Group I (Control-ischeamia-reperfusion) \u0026amp; Group II(ischeamic preconditioning)(P\u0026lt;0.05), b-indicates comparison between Group I(Control-ischeamia-reperfusion) \u0026nbsp;\u0026amp; Group III(Ranolazine)(P\u0026lt;0.05), c indicates comparison between Group IV(Ranolazine+L-NAME) vs Group III(Ranolazine)(P\u0026lt;0.05), d indicates comparison between Group V(Ranolazine+Aminoguanidine) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). e-indicates comparison between Group VI(Ranolazine+Theophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), f-indicates comparison between Group VII(Ranolazine+Aminophylline) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), g indicates comparison between Group VIII(Enalapril) vs Group III(Ranolazine) (P\u0026lt;0.05), h indicates comparison between Group IX(Ranolazine+Losartan) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05). i-indicates comparison between Group X(Ranolazine+5-Hydroxy Decanoate) \u0026amp; Group III(Ranolazine) (P\u0026lt;0.05), j-indicates comparison between Group XI(Ranolazine+Glimepiride) \u0026amp; Group III(Ranolazine)(P\u0026lt;0.05).\u003c/p\u003e"},{"header":"4. Discussion","content":"\u003cp\u003e\u003cstrong\u003eMechanism of action of Ranolazine\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNumerous studies demonstrated ranolazine as cardioproective in clinical as well as in animal studies [15-17]. In its Ranolazine Ischemia Na+ Overload Mechanical dysfunction \u0026uarr; diastolic tension \u0026darr; contractility Ca2+ Overload Electrical Dysfunction Arrhythmias NCX \u0026uarr; late INa Na/K-ATPase NHE O2 Supply \u0026amp; Demand \u0026uarr; ATP consumption \u0026darr; ATP formation. Late INa under normal and increased late INa under pathophysiological conditions, late INa inhibition with ranolazine reverse mode (usually during the action potential), it brings in calcium into the cell in exchange to trans-sarcolemma elimination of sodium. The activity and direction of transport depends on the abundance of the protein as well as on the membrane potential, intracellular sodium and intracellular calcium concentration. Sodium accumulation following myocardial hypoxia (i.e., through late INa) promotes reverse mode sodium\u0026ndash;calcium exchange and therefore reduces the overall cellular capacity to eliminate calcium outside of the cytosol (Figure 5; Figure 6) [14-17].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIschemic Pre-conditioning and its mediators\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIschemia is defined as a state in which the blood flow is partially or completely blocked in a tissue or organ. When ischemia persists, necrosis and cell death occur. reperfusion injury (IRI). Renal IRI is one of the main causes of acute kidney injury and occurs in various clinical situations, such as partial nephrectomy, renal transplantation, aortic cross clamping surgery, cardiopulmonary resuscitation, sepsis, and shock. Hydrogen sulfide, superoxide dismutase (SOD), apocynin, allopurinol, hypothermia, ischemic preconditioning (IPC), and remote ischemic preconditioning (RIPC) were found to reduce IRI. Remote ischemic preconditioning, in which the IPC of one organ protects another distant organ against prolonged IRI, may attenuate renal injury induced by IRI. Brief ischemia and reperfusion produce large amounts of oxygen-derived free radicals, which in turn release antioxidants that act as free radical scavengers. Although the underlying protective mechanisms of RIPC have not been fully understood, nitric oxide (NO) generated by RIPC is considered to have a protective effect against IRI of the heart, brain, and liver (Figure 7) [18]. Role of nitric oxide, adenosine, Bradykinin \u0026amp; K\u003csup\u003e+\u003c/sup\u003eATPase has been previously reported in ischemic preconditioning that have cardioprotective effect [19-41].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003c/strong\u003e\u003cstrong\u003ePrevious findings about CK-MB and LDH in cardioprotection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCK-MB and LDH are widely used as markers to assess the extent of myocardial damage and ischemia-reperfusion injury. In the context of cardioprotective research, they serve as valuable indicators of the effectiveness of various interventions, including preparedness strategies, pharmacological agents, and other therapeutic approaches to minimize tissue damage in ischemic events. In conclusion, both CK-MB and LDH play an important role as markers of myocardial and cellular damage in cardioprotective studies. Monitoring their levels can shed light on the effects of various harm reduction strategies and interventions in ischemia-reperfusion injury [42].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIschemic preconditioning and Ranolazine has demonstrated cardioprotection because they have decreased LDH and CK-MB in ischemic reperfusion induced cardiac injury. As per previous literature ischemic preconditioning has brought cardioprotection by nitric oxide, adenosine, bradykinin and K\u003csup\u003e+\u003c/sup\u003eATPase mediated pathway. Now our research question is that Ranolazine is also mediating cardioprotection by these pathways. However it is confirmed that adenosine levels are increased in ranolazine induced cardioprotection in dogs [24].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOur study confirms that Ranolazine induced cardioprotection involves nitric oxide, adenosine, bradykinin and K\u003csup\u003e+\u003c/sup\u003eATPase mediated pathway as L-NAME, Aminoguanidine, Theophylline, Aminophylline, Enalapril, Losartan, 5-Hydroxydecanoate and Glimepiride abolished ranolazine induced cardioprotection.\u003c/p\u003e\n\u003cp\u003eL-NAME, Aminoguanidine, Theophylline, Aminophylline, Enalapril, Losartan, 5-Hydroxydecanoate and Glimepiride increases infarct size, LDH and CK-MB in ranolazine treatment groups. Hence, in conclusion our research findings suggest role of nitric oxide, adenosine, bradykinin and K\u003csup\u003e+\u003c/sup\u003eATPase in Ranolazine induced cardioprotection as secondary messenger like ischemic preconditioning. Hence ranolazine as drug can replace surgical ischemic preconditioning before interventional techniques like coronary artery bypass graft surgery (CABG) and heart transplantation for better patient compliance.\u003c/p\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eIn Ranolazine treated group with both nitric oxide inhibitors\u003cb\u003e-\u003c/b\u003e L-NAME and aminoguanidine, both adenosine inhibitors- Theophylline and Aminophylline, both Bradykinin inhibitors- Enalapril and Losartan \u0026amp; both K\u003csup\u003e+\u003c/sup\u003eATPase inhibitors- 5-Hydroxydecanoate and Glimepiride treatment group increased percentage myocardial infarction, lactate dehydrogenase, and CK-MB. Hence, in conclusion our research findings suggest role of nitric oxide, adenosine, bradykinin and K\u003csup\u003e+\u003c/sup\u003eATPase in cardioprotection as secondary messenger in ischeamic preconditioning. As a result, we also conclude that nitric oxide, adenosine, bradykinin and K\u003csup\u003e+\u003c/sup\u003eATPase function as a secondary messenger in the cardioprotection caused by ranolazine. Hence ranolazine as drug can replace surgical ischemic preconditioning and used in ischemic heart disease and before interventional techniques like coronary artery bypass graft surgery (CABG) and heart transplantation for better patient compliance.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAll Authors contributed to execute experimental, manuscript preparation, data analysis, litrature survey etc.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability statement \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eThe datasets used and/or analysed during the current study available from the corresponding author on reasonable request.\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026ldquo;Availability of Data and Materials\u0026rdquo; statements: All authors declare that excel sheet raw data and supplementary files (Ethical approvals from Indian Government approved for experiments on vertebrates [Wistar Albino Rats] has been attached as supplementary files to be shared in the said manuscript.\u003c/p\u003e\n\u003cp\u003e\u0026quot;Authors reporting experiments on live vertebrates have included the appropriate ethics declarations in the Methods section of our manuscript\u0026rdquo;. We checked that the information provided is unambiguous using the following requirements:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e- I \u003cstrong\u003econfirm that all methods were carried out in accordance with relevant guidelines and regulations\u003c/strong\u003e\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e- I \u003cstrong\u003econfirm that all methods are reported in accordance with ARRIVE guidelines\u0026nbsp;\u003c/strong\u003e\u003c/strong\u003e(https://arriveguidelines.org).\u003c/p\u003e\n\u003cp\u003eFor further information, I have gone through guidelines using the following link \u0026amp; the research is in accordance to these policies:\u003c/p\u003e\n\u003cp\u003ehttps://www.nature.com/srep/journal-policies/editorial-policies#experimental-subjects\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLi, J., Zhang, H. \u0026amp; Zhang, C. Role of inflammation in the regulation of coronary blood flow in ischemia and reperfusion: mechanisms and therapeutic implications. J Mol Cell Cardiol 52(4), 865\u0026ndash;72. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.yjmcc.2011.08.027\u003c/span\u003e\u003cspan address=\"10.1016/j.yjmcc.2011.08.027\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKubler, W. \u0026amp; Haass, M. Cardioprotection: definition, classification, and fundamental principles. Heart 75(4), 330\u0026ndash;3. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1136/hrt.75.4.330\u003c/span\u003e\u003cspan address=\"10.1136/hrt.75.4.330\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1996).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDirksen, M.T., Laarman, G.J., Simoons, M.L. \u0026amp; Duncker, D.J. Reperfusion injury in humans: a review of clinical trials on reperfusion injury inhibitory strategies. Cardiovasc Res 74(3), 343\u0026ndash;55. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.cardiores.2007.01.014\u003c/span\u003e\u003cspan address=\"10.1016/j.cardiores.2007.01.014\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2007).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcCafferty, K., Forbes, S., Thiemermann, C. \u0026amp; Yaqoob, M.M. The challenge of translating ischemic conditioning from animal models to humans: the role of comorbidities. Dis Model Mech 7(12), 1321\u0026ndash;33. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1242/dmm.016741\u003c/span\u003e\u003cspan address=\"10.1242/dmm.016741\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGattullo, D., Linden, R.J., Losano, G., Pagliaro, P. \u0026amp; Westerhof, N. Ischaemic preconditioning changes the pattern of coronary reactive hyperaemia in the goat: role of adenosine and nitric oxide. Cardiovasc Res 42(1), 57\u0026ndash;64. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/s0008-6363(98)00319-8\u003c/span\u003e\u003cspan address=\"10.1016/s0008-6363(98)00319-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1999).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCalder\u0026oacute;n-S\u0026aacute;nchez, E.M., Dom\u0026iacute;nguez-Rodr\u0026iacute;guez, A., L\u0026oacute;pez-Hald\u0026oacute;n, J., Jim\u0026eacute;nez-Navarro, M.F., G\u0026oacute;mez, A.M., Smani, T. \u0026amp; Ord\u0026oacute;\u0026ntilde;ez, A. Cardioprotective Effect of Ranolazine in the Process of Ischemia-reperfusion in Adult Rat Cardiomyocytes. Rev Esp Cardiol (Engl Ed). 69(1), 45\u0026ndash;53. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.rec.2015.02.027\u003c/span\u003e\u003cspan address=\"10.1016/j.rec.2015.02.027\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2016 Jan).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHale, S.L., Leeka, J.A. \u0026amp; Kloner, R.A. Improved Left Ventricular Function and Reduced Necrosis after Myocardial Ischemia/Reperfusion in Rabbits Treated with Ranolazine, an Inhibitor of the Late Sodium Channel. J Pharmacol Exp Ther. 318(1), 418\u0026ndash;23. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1124/jpet.106.103242\u003c/span\u003e\u003cspan address=\"10.1124/jpet.106.103242\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2006).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCheng, J.W. Ranolazine for the management of coronary artery disease. \u003cem\u003eClin Ther\u003c/em\u003e. 28(12),1996\u0026ndash;2007. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.clinthera.2006.12.009\u003c/span\u003e\u003cspan address=\"10.1016/j.clinthera.2006.12.009\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2006)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBelardinelli, L., Shryock, J.C. \u0026amp; Fraser H. The mechanism of ranolazine action to reduce ischemia-induced diastolic dysfunction. Eur Heart J Suppl. 8(Suppl_A), A10\u0026ndash;3. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/EURHEART/SUI091\u003c/span\u003e\u003cspan address=\"10.1093/EURHEART/SUI091\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2006).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRayner-Hartley, E. \u0026amp; Sedlak, T. Ranolazine: a contemporary review. Journal of the American Heart Association. 5(3), e003196. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1161/JAHA.116.003196\u003c/span\u003e\u003cspan address=\"10.1161/JAHA.116.003196\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNilsson, B.O. Biological effects of aminoguanidine: an update. Inflamm Res. 48(10), 509\u0026ndash;15. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s000110050495\u003c/span\u003e\u003cspan address=\"10.1007/s000110050495\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. doi: 10.1007/s000110050495 (1999)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWolf, R.E., Graeber, G.M., Burge, J.R., DeShong, J.L., MacDonald, J.L. \u0026amp; Zajtchuk, R. Evaluation of Serum Creatine Kinase and Lactate Dehydrogenase in Experimental Myocardial Infarction, Atriotomies, and Thoracotomies. The Annals of Thoracic Surgery. 41(4), 378\u0026ndash;386, \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0003-4975(10)62690-2\u003c/span\u003e\u003cspan address=\"10.1016/S0003-4975(10)62690-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1986).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003e[15]. Sharma, A.K., Munajjam, A., Vaishnav, B., Sharma, R., Kishore, K., Sharma, A., Sharma, D., Kumari, R., Tiwari, A. \u0026amp; Srinivasan, B.P. Remote preconditioning by aortic constriction: Does it afford cardioprotection similar to classical or other remote ischemic preconditioning? Role of inducible nitric oxide synthase. CVD Prevention and Control. 6(1), 15\u0026ndash;33. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/S1674-8301(12)60004-9\u003c/span\u003e\u003cspan address=\"10.1016/S1674-8301(12)60004-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2011).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLangendorff, O. Untersuchugen am uberlebenden Saugethieherzen. Pflugers Arch. 61, 291\u0026ndash;307. (1895)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003e[13]. Kutsal, A., Saydam, G.S., Y\u0026uuml;cel, D. \u0026amp; Balk, M. Changes in the serum levels of CK-MB, LDH, LDH1, SGOT and myoglobin due to cardiac surgery. J Cardiovasc Surg (Torino). 32(4), 516\u0026ndash;22. PMID: 1864883 (1991).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003e[14]. Jung, H., Choi, E.K., Baek, S.I., Cho, C., Jin, Y., Kwak, K.H., Jeon, Y., Park, S.S., Kim, S. \u0026amp; Lim, D.G. The effect of nitric oxide on remote ischemic preconditioning in renal ischemia reperfusion injury in rats. Dose-Response. 17(2), 1559325819853651. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1177/1559325819853651\u003c/span\u003e\u003cspan address=\"10.1177/1559325819853651\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEfentakis, P., Andreadou, I., Sophia-Iris, B., Vasileiou, S., Dagres, N., Zoga, A., Lougiakis, N., Kremastinos, D.T. \u0026amp; Iliodromitis, E.K. Ranolazine triggers pharmacological preconditioning and postconditioning in anesthetized rabbits through activation of RISK pathway. Eur J Pharmacol. 789, 431\u0026ndash;438. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.ejphar.2016.08.001\u003c/span\u003e\u003cspan address=\"10.1016/j.ejphar.2016.08.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTawfik, M.K. \u0026amp; Ameen, A.M. Cardioprotective effect of ranolazine in nondiabetic and diabetic male rats subjected to isoprenaline-induced acute myocardial infarction involves modulation of AMPK and inhibition of apoptosis. Can J Physiol Pharmacol. 97(7), 661\u0026ndash;674. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1139/cjpp-2018-0571\u003c/span\u003e\u003cspan address=\"10.1139/cjpp-2018-0571\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLa Padula, P.H., Etchegoyen, M., Czerniczyniec, A., Piotrkowski, B., Arnaiz, S.L., Milei, J. \u0026amp; Costa, L.E. Cardioprotection after acute exposure to simulated high altitude in rats. Role of nitric oxide. Nitric Oxide. 73, 52\u0026ndash;9. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.niox.2017.12.007\u003c/span\u003e\u003cspan address=\"10.1016/j.niox.2017.12.007\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKanno S, Lee PC, Zhang Y, Ho C, Griffith BP, Shears LL, Billiar TR. Attenuation of myocardial ischemia/reperfusion injury by superinduction of inducible nitric oxide synthase. Circulation. 101(23), 2742\u0026ndash;8. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1161/01.cir.101.23.2742\u003c/span\u003e\u003cspan address=\"10.1161/01.cir.101.23.2742\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2000)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKatakam, P.V., Ujhelyi, M.R., Hoenig, M. \u0026amp; Miller, A.W. Metformin improves vascular function in insulin-resistant rats. Hypertension. 35(1), 108\u0026ndash;12. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1161/01.hyp.35.1.108\u003c/span\u003e\u003cspan address=\"10.1161/01.hyp.35.1.108\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2000)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMurry, C.E., Jennings, R.B. \u0026amp; Reimer, K.A. Preconditioning with ischemia: a delay of lethal cell injury in ischemic myocardium. Circulation. 74(5), 1124\u0026ndash;36. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1161/01.cir.74.5.1124\u003c/span\u003e\u003cspan address=\"10.1161/01.cir.74.5.1124\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1986)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNapoli, C. New-onset angina preceding acute myocardial infarction is associated with improved contractile recovery after thrombolysis. Eur Heart J. 19(3), 411\u0026ndash;9. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1053/euhj.1997.0748\u003c/span\u003e\u003cspan address=\"10.1053/euhj.1997.0748\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1998).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu, G.S, Thornton, J., Van Winkle, D.M., Stanley, A.W., Olsson, R.A. \u0026amp; Downey, J.M. Protection against infarction afforded by preconditioning is mediated by A1 adenosine receptors in rabbit heart. Circulation. 84(1), 350\u0026ndash;6 doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1161/01.cir.84.1.350\u003c/span\u003e\u003cspan address=\"10.1161/01.cir.84.1.350\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1991).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLe, D.E., Davis, C.M., Wei, K., Zhao, Y., Cao, Z., Nugent, M., Scott, K.L., Liu, L., Nagarajan, S., Alkayed, N.J. \u0026amp; Kaul, S. Ranolazine may exert its beneficial effects by increasing myocardial adenosine levels. American Journal of Physiology-Heart and Circulatory Physiology. 318(1), H189-202. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1152/ajpheart.00217.2019\u003c/span\u003e\u003cspan address=\"10.1152/ajpheart.00217.2019\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFan, H., Sun, B., Gu, Q., Lafond-Walker, A., Cao, S. \u0026amp; Becker, L.C. Oxygen radicals trigger activation of NF-κB and AP-1 and upregulation of ICAM-1 in reperfused canine heart. Am J Physiol Circ Physiol. 282(5), H1778\u0026ndash;86. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1152/ajpheart.00796.2000\u003c/span\u003e\u003cspan address=\"10.1152/ajpheart.00796.2000\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2002).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStarkopf, J., Bugge, E. \u0026amp; Ytrehus, K. Preischaemic bradykinin and ischaemic preconditioning in functional recovery of the globally ischaemic rat heart. Cardiovasc Res. 33(1), 63\u0026ndash;70. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/s0008-6363(96)00195-2\u003c/span\u003e\u003cspan address=\"10.1016/s0008-6363(96)00195-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1997).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePan, H.L., Chen, S.R., Scicli, G.M. \u0026amp; Carretero, O.A. Cardiac interstitial bradykinin release during ischemia is enhanced by ischemic preconditioning. Am J Physiol Circ Physiol. 279(1), H116\u0026ndash;21. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1152/ajpheart.2000.279.1.H116\u003c/span\u003e\u003cspan address=\"10.1152/ajpheart.2000.279.1.H116\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2000)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWall, T.M., Sheehy, R. \u0026amp; Hartman, J.C. Role of bradykinin in myocardial preconditioning. J Pharmacol Exp Ther. 270(2), 681\u0026ndash;9. PMID: 8071859 (1994).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSheng, Z., Yao, Y., Li, Y., Yan, F., Huang, J. \u0026amp; Ma, G. Bradykinin preconditioning improves therapeutic potential of human endothelial progenitor cells in infarcted myocardium. PLoS One. 8(12), e81505. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1371/journal.pone.0081505\u003c/span\u003e\u003cspan address=\"10.1371/journal.pone.0081505\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2013)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrzyklenk, K., Bauer, B., Ovize, M., Kloner, R.A. \u0026amp; Whittaker P. Regional ischemic\u0026rsquo;preconditioning\u0026rsquo;protects remote virgin myocardium from subsequent sustained coronary occlusion. Circulation. 87(3), 893\u0026ndash;9. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1161/01.cir.87.3.893\u003c/span\u003e\u003cspan address=\"10.1161/01.cir.87.3.893\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1993)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRegoli, D. \u0026amp; Barabe, J. Pharmacology of bradykinin and related kinins. Pharmacol Rev. 32(1), 1\u0026ndash;46. PMID: 7015371. (1980)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCarretero, O.A., Miyazaki, S. \u0026amp; Scicli, A.G. Role of kinins in the acute antihypertensive effect of the converting enzyme inhibitor, captopril. Hypertension. 3(1), 18\u0026ndash;22. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1161/01.hyp.3.1.18\u003c/span\u003e\u003cspan address=\"10.1161/01.hyp.3.1.18\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1981)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eClark, B., Wyatt, K.M. \u0026amp; Mccormack, J.G. Ranolazine increases active pyruvate dehydrogenase in perfused normoxic rat hearts: evidence for an indirect mechanism. J. Mol. Cell Cardiol. 28(2), 341\u0026ndash;350. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1006/jmcc.1996.0032\u003c/span\u003e\u003cspan address=\"10.1006/jmcc.1996.0032\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1996).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHanley, P.J., Mickel, M., L\u0026ouml;ffler, M., Brandt, U. \u0026amp; Daut J. KATP channel-independent targets of diazoxide and 5‐hydroxydecanoate in the heart. J Physiol. 542(Pt 3), 735\u0026ndash;41. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1113/jphysiol.2002.023960\u003c/span\u003e\u003cspan address=\"10.1113/jphysiol.2002.023960\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2002)..\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGross, G.J. \u0026amp; Auchampach, J.A. Blockade of ATP-sensitive potassium channels prevents myocardial preconditioning in dogs. Circulation Research. 70(2), 223\u0026ndash;33. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1161/01.res.70.2.223\u003c/span\u003e\u003cspan address=\"10.1161/01.res.70.2.223\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1992)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAli, K., Morimoto, M., Fukaya, Y. \u0026amp; Furukawa, Y. Improvement of cardiac function impaired by repeated ischemic arrests in isolated rat hearts. The Annals of Thoracic Surgery. 55(4), 902\u0026ndash;7. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/0003-4975(93)90114-w\u003c/span\u003e\u003cspan address=\"10.1016/0003-4975(93)90114-w\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1993).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOlders, J., Turek, Z., Evers, J., Hoofd, L., Oeseburg, B. \u0026amp; Kreuzer, F. Comparison of Tyrode and blood perfused working isolated rat hearts. Adv Exp Med Biol. 277, 403\u0026ndash;13. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/978-1-4684-8181-5_46\u003c/span\u003e\u003cspan address=\"10.1007/978-1-4684-8181-5_46\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1990).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGettes, L.S. What are the effects of potassium on the electrophysiology of acute ischemia. Life-Threatening Arrhythmias During Ischemia and Infarction. New York, NY: Raven Press Publishers. 77\u0026ndash;90. (1987).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCurtis, M.J., Macleod, B.A. \u0026amp; Walker, M.J. Models for the study of arrhythmias in myocardial ischaemia and infarction: the use of the rat. Journal of Molecular and Cellular Cardiology. 19(4), 399\u0026ndash;419. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/s0022-2828(87)80585-0\u003c/span\u003e\u003cspan address=\"10.1016/s0022-2828(87)80585-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1987)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchaper, W., Binz, K., Sass, S. \u0026amp; Winkler, B. Influence of collateral blood flow and of variations in MVO2 on tissue-ATP content in ischemic and infarcted myocardium. Journal of Molecular and Cellular Cardiology. 19(1), 19\u0026ndash;37. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/s0022-2828(87)80542-4\u003c/span\u003e\u003cspan address=\"10.1016/s0022-2828(87)80542-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1987).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCarmeliet E. Oral antidiabetics and hypoxic shortening of the cardiac action potential. Eur Heart J. 8(Suppl 2), 315\u0026thinsp;\u0026ndash;\u0026thinsp;27. (1987).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAmani, M., Jeddi, S., Ahmadiasl, N., Usefzade, N. \u0026amp; Zaman J. Effect of HEMADO on Level of CK-MB and LDH Enzymes after Ischemia/Reperfusion Injury in Isolated Rat Heart. Bioimpacts. 3(2), 101\u0026ndash;4. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.5681/bi.2013.003\u003c/span\u003e\u003cspan address=\"10.5681/bi.2013.003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2013)\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Ranolazine, Ischemic Preconditioning, Nitric Oxide, Adenosine, Bradykinin, K+ATPase","lastPublishedDoi":"10.21203/rs.3.rs-3825042/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3825042/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjectives\u003c/strong\u003e: This study was to investigate cardioprotective effects of ranolazine and to explore possible secondary mechanisms beyond the cellular studies have demonstrated inhibition of late sodium channel(I\u003csub\u003eNa\u003c/sub\u003eL) leads to reduction in calcium load during cardiac ischemia. We hypothesized that ranolazine-induce Nitric oxide, Adenosine, Bradykinin and K+ATPase like ischemic preconditioning.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e: Ischemia-reperfusion injury was established using Langendroff’s technique. 20minute ischemia and 40minute reperfusion to coronary artery to isolated heart was model of myocardial infarction. There were following groups: Control(Ischeamia-Reperfusion), Ischemic preconditioning, ranolazine(100µmol/L), ranolazine+L-NAME(30µmol/L) and ranolazine+Aminoguanidine(30µmol/L), ranolazine+Theophylline(50µmol/L), ranolazine+Aminophylline(50µmol/L), ranolazine+Enalapiril(100µmol/L), ranolazine+Losartan(50µmol/L), ranolazine+5-hydroxydecanoate(30µmol/L), ranolazine+glimepiride(50µmol/L) in perfusate.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e: Ranolazine found cardioprotection(Infarct Size:5.334± 0.422 v/s control 65.667±0.558; LDH:101.500±1.147U/L v/s control 155.500±0.957U/L; CK-MB: 100.167±1.302U/L v/s control 198.500±1.803U/L)\u003c/p\u003e\n\u003cp\u003eIschemic Preconditioning found cardioprotection(Infarct Size:5.1667±0.478 v/s control 65.667±0.558; LDH:101.667±2.789U/L v/s control 155.500±0.958U/L; CK-MB: 97.167±1.721U/L v/s control 198.500±1.803U/L)\u003c/p\u003e\n\u003cp\u003eRanolazine+L-NAME(Infarct Size:64.167±0.872 v/s control ranolazine 5.334± 0.422; LDH: 154.667±1.256U/L v/s control ranolazine 101.500±1.147; CK-MB:200.167±1.537U/L v/s control ranolizine 100.167±1.302U/L)\u003c/p\u003e\n\u003cp\u003eRanolazine+Aminoguanidine(Infarct Size: 64.500±0.885 v/s control ranolazine 5.334± 0.422; LDH: 154.833±1.1377U/L v/s control ranolazine 101.500±1.147U/L; CK-MB:198.333±1.145U/L v/s control ranolizine 100.167±1.302U/L)\u003c/p\u003e\n\u003cp\u003eRanolazine+Theophylline (Infarct Size: 64.667±0.760 v/s control ranolazine 5.334± 0.422; LDH: 155.167±1.301U/L v/s control ranolazine 101.500±1.147; CK-MB:199.167±1.376U/L v/s control ranolizine 100.167±1.302U/L)\u003c/p\u003e\n\u003cp\u003eRanolazine+Aminophylline (Infarct Size: 65.167±0.601 v/s control ranolazine 5.334± 0.422; LDH: 155.333±0.615U/L v/s control ranolazine 101.500±1.147U/L; CK-MB: 199.500± 1.765U/L v/s control ranolizine 100.167±1.302U/L)\u003c/p\u003e\n\u003cp\u003eRanolazine+Enalapiril (Infarct Size: 64.667±0.615 v/s control ranolazine 5.334± 0.422; LDH: 154.667± 1.085U/L v/s control ranolazine 101.500±1.147; CK-MB: 201.8333±1.990U/L v/s control ranolizine 100.167±1.302U/L)\u003c/p\u003e\n\u003cp\u003eRanolazine+Losartan (Infarct Size: 63.667±1.282 v/s control ranolazine 5.334± 0.422; LDH: 155.167± 0.909U/L v/s control ranolazine 101.500±1.147U/L; CK-MB: 199.500±2.349U/L v/s control ranolizine 100.167±1.302U/L)\u003c/p\u003e\n\u003cp\u003eRanolazine+5-hydroxydecanoate (Infarct Size: 63.833±1.352 v/s control ranolazine 5.334± 0.422; LDH: 154.667±1.054U/L v/s control ranolazine 101.500±1.147; CK-MB: 201.833±1.815U/L v/s control ranolizine 100.167±1.302U/L)\u003c/p\u003e\n\u003cp\u003eRanolazine+Glimepiride (Infarct Size: 63.667±0.989 v/s control ranolazine 5.334± 0.422; LDH: 155.833±1.352U/L v/s control ranolazine 101.500±1.147U/L; CK-MB: 199.833±1.579U/L v/s control ranolizine 100.167±1.302U/L)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e: As per confirmation Ranolazine and ischemic preconditioning have brought cardioprotection as reduced Infract Size, LDH \u0026amp; CK-MB. Wereas, treatment of L-NAME, Aminoguanidine, Theoplylline, Aminoplylline, Enalapiril, Losartan, 5-hydroxydecanoate \u0026amp; Glimepiride increased infract size, LDH \u0026amp; CK-MB. Hence it is proved that ranolazine involves Nitric oxide, Adenosine, Bradykinin and K+ATPase as secondary messenger in cardioprotection like ischemic preconditioning.\u003c/p\u003e","manuscriptTitle":"Ranolazine Exert its Beneficial Effects in myocardial infarction like Ischemic preconditioning mediators by Increasing Myocardial Nitric oxide, Adenosine, Bradykinin and K+ATPase Levels","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-01-17 15:44:13","doi":"10.21203/rs.3.rs-3825042/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f6c1e732-6116-411e-9b36-3a5fb731dbba","owner":[],"postedDate":"January 17th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":28163035,"name":"Biological sciences/Drug discovery"},{"id":28163036,"name":"Health sciences/Cardiology"}],"tags":[],"updatedAt":"2024-01-27T06:44:12+00:00","versionOfRecord":[],"versionCreatedAt":"2024-01-17 15:44:13","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3825042","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3825042","identity":"rs-3825042","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}