The role and significance of endomorphin-1 and μ-opioid receptor in rats with endometriosis

Lijun Duan, Jinyang Wang, Xiaotong Sun, Xueping Yang, Long Shan, Shan Long, Yan Liu, Hailin Wang
Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology · 2016 · vol. 32(11) , pp. 912–915 · doi:10.1080/09513590.2016.1190816 · PMID:27252115 · W2416864960
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Endometriosis model rats showed increased endomorphin-1 and decreased reproductive hormones, with naloxone reversing these changes, suggesting endomorphin-1 regulates the hypothalamus-pituitary-ovarian axis.

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Abstract

Endomorphin-1 (EM-1) was reported to have very high affinity and selectivity for μ-opioid receptor (MOR). However, it remained unclear whether EM-1 and MOR were involved in the pathologies of endometriosis resulting in reduced fertility. In this study, RT-PCR, radioimmunoassay, immunohistochemistry, and Western blot were used, respectively. The results showed that the immune positive cells of EM-1 in hypothalamus, pituitary, and ovaries were significantly increased in endometriosis model rats, accompanied by the increase of plasma level of EM-1 and the decrease of follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and progesterone (P). Interestingly, EM-1 was negatively correlated with FSH and LH (p < 0.05). More importantly, Naloxone (MOR antagonist) can significantly reduce the levels of EM-1 in serum, hypothalamus, pituitary, and ovaries, while increased the levels of FSH and LH. In conclusion, our results suggested that EM-1 may be involved in the pathogenesis of the endometriosis-associated infertility by regulating hypothalamus-pituitary-ovarian axis, and Naloxone may be a new alternative drug for the treatment of endometriosis.

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Condition tags

endometriosisinfertility

MeSH descriptors

Endometriosis Oligopeptides Receptors, Opioid, mu Animals Disease Models, Animal Endometriosis Endometriosis Female Oligopeptides Oligopeptides Rats Rats, Wistar Receptors, Opioid, mu

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