Effects of pinealectomy and melatonin supplementation on endometrial explants in a rat model.

Objective: To determine the effects of pinealectomy on endometrial explants in rats and evaluate the activity of superoxide dismutase (SOD) and catalase (CAT) and the levels of malondialdehyde (MDA) in the rat endometriosis model.
Study Design: Rats with experimentally induced endometriosis were randomly divided into three groups after second-look laparotomies. Group 1 (pinealectomy, n = 8) and Group 2 (pinealectomy+melatonin, n = 8) underwent pinealectomies after the second-look laparotomies. Group 3 was presented as control group (vehicle solution+without pinealectomy (n = 6)). Melatonin was administered intraperitoneally for 4 weeks in Group 2, whereas an equal volume of vehicle solution was given to Groups 1 and 3. Evaluation of the volume of the endometrial explants, histopathological examination and preservation of explant epitheliums according to the scoring system were undertaken.
Results: There was a statistically significant increase in spherical explant volumes of Group 1 compared to Groups 2 and 3. In Group 1, the level of MDA was significantly higher and SOD and CAT activity was significantly lower compared to Groups 2 and 3. A statistically significant increase in the epithelial lining scores of explants was noted in Group 1 compared to Groups 2 and 3.
Conclusion: The effects of pinealectomy on the progression of endometriosis explants were reversed by melatonin.
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