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.

Intraperitoneal administration of single dose type I collagen or low dose melatonin to prevent intraperitoneal adhesion formation: a comparative study.

OBJECTIVE: To compare the prevention of adhesion formation by type I collagen or melatonin solutions in the rat model. STUDY DESIGN: A total of 40 female Wistar albino rats were randomly assigned to four groups-type I collagen, melatonin, vehicle control and sham groups. Following midline laparotomy, a standard injury was made on the right uterine horn using bipolar cautery. The animals in the sham group underwent midline laparatomy only. One milliliter of type I collagen, melatonin or vehicle control was instilled onto the injured area immediately before abdominal closure. Fourteen days after the surgery, the type and extent of adhesion formation as well as the uterine horn tissue superoxide dismutase (SOD) and catalase (CAT) activity, and malondialdehyde (MDA) levels were measured. RESULTS: Both the type and extent of adhesion formation were significantly lower in the type I collagen and melatonin groups compared to the control group. The tissue SOD and CAT activity was significantly higher, and MDA levels were significantly lower in the type I collagen and melatonin groups compared to the control group. CONCLUSION: Intraperitoneal administration of type I collagen or low dose melatonin solution onto the injured areas may be an attractive adjuvant to reduce postoperative adhesion formation.