Melatonin reduces torsion-detorsion injury in rat ovary: biochemical and histopathologic evaluation.

Abstract

This experimental study was designed to determine the effects of melatonin on the levels of malondialdehyde (MDA), reduced glutathione (GSH), xanthine oxidase (XO) after adnexial torsion/detorsion (ischemia/reperfusion, I/R) of the ovaries of in rats. Forty adult albino rats were divided into five groups: sham operation, torsion, I/R plus saline, I/R plus melatonin and torsion plus melatonin. Rats in the sham-operated group underwent a surgical procedure similar to the other groups but the adnexa was not occluded. Rats in the torsion group were killed after adnexal torsion for 3 hr. Melatonin and saline were injected intraperitoneally (10 mg/kg) 30 min before detorsion to the I/R plus melatonin group and I/R plus saline group respectively. After 3 hr of ovarian detorsion, the rats were killed and ovaries were removed. Melatonin was injected intraperitoneally (10 mg/kg) 30 min before torsion to the torsion plus melatonin group. After 3 hr of ovarian torsion, the rats were killed and ovaries were harvested. The tissue levels of MDA, GSH and XO were measured. MDA and XO levels in the I/R plus saline group increased significantly when compared with torsion and sham-operated groups (P < 0.001). MDA and XO levels in the I/R plus melatonin group were lower than I/R plus saline and differences between the two groups were statistically significant (P < 0.001). GSH levels in the I/R plus saline group decreased significantly when compared with ischemia and sham-operated groups (P < 0.001). GSH levels in the I/R plus melatonin treated rats were significantly higher than I/R plus saline and ischemia groups (P < 0.001). The tissue levels of XO, MDA and GSH were similar between ischemia and ischemia plus melatonin groups. Morphologically, polymorphonuclear neutrophil infiltration and vascular dilatation were obvious in the I/R-damaged ovaries, and the changes also partially reversed by melatonin. This study demonstrates that melatonin protects the ovaries against oxidative damage associated with reperfusion following an ischemic insult.