ORIGINAL ARTICLE Reproductive biology Expression of eicosanoid biosynthetic and catabolic enzymes in peritoneal endometriosis

background: Increased peritoneal eicosanoid concentrations have been reported in endometriosis patients and might be important in disease-associated pain and inflammation. Here, we evaluated the expression of key biosynthetic and catabolic enzymes involved in this abnormal eicosanoid production in peritoneal macrophages and endometriotic lesions. methods: Peritoneal macrophages, endometriotic lesions and matched eutopic endometrium were collected from endometriosis patients (n 40). Peritoneal macrophages and eutopic endometrium samples were also collected from disease-free women (n 25). Expression of type IIA secretory phospholipase A2 (sPLA2-IIA), cyclooxygenase-2 (COX-2), microsomal prostaglandin E synthase-1 (mPGES-1), 15-hydroxyprostaglandin dehydrogenase (15-PGDH) and 5-lipoxygenase (5-LO) was quantified by real-time PCR, and these five key enzymes were localized by immunohistochemistry. results: sPLA2-IIA, COX-2 and mPGES-1 mRNA was significantly increased in peritoneal macrophages of endometriosis patients com-pared with controls (P 0.006, P 0.016 and P 0.025, respectively). In endometriosis patients, sPLA2-IIA, mPGES-1 and 15-PGDH mRNA was significantly enhanced in peritoneal lesions compared with matched eutopic endometrium (P, 0.001, P, 0.001 and P 0.005, respectively). In eutopic endometrium, a significant decrease in 15-PGDH mRNA was found in the endometriosis group compared with controls (P 0.023). Finally, sPLA2-IIA, COX-2, mPGES-1 and 15-PGDH immunostaining was found mainly in endometrial glands, whereas 5-LO was distributed throughout the glands and stroma. conclusions: Our study highlights an imbalance between eicosanoid biosynthesis and degradation in endometriosis patients. Both