Effect of melatonin on testicular ischemia/reperfusion injury in rats: is this effect related to the proinflammatory cytokines?

OBJECTIVE

To determine whether the protective effect of melatonin in testicular ischemia/reperfusion (IR) injury is mediated by the proinflammatory molecules.

DESIGN

Experimental study.

SETTING

University pharmacology laboratory.

ANIMAL(S): Fifty-six 8-week-old male Wistar albino rats.

INTERVENTION(S): Left testicular artery and vein was occluded for 1 hour, followed by 3 hours or 24 hours of reperfusion. Melatonin (10 mg/kg IP) or vehicle (1% ethanol in saline) was given 10 minutes before ischemia.

MAIN OUTCOME MEASURE(S): Malondialdehyde (MDA), protein carbonyl (PC) content, myeloperoxidase (MPO) activity, and proinflammatory cytokines TNF-alpha, IL-1beta, and IL-6 were examined in testicular tissue after 3 hours of reperfusion. Histologic examination was made after 24 hours of reperfusion.

RESULT(S): The MDA, PC, and MPO levels in testicular tissue increased significantly after IR, but the proinflammatory cytokine levels did not change. Melatonin treatment decreased lipid and protein oxidation and ameloriated histopathologic alterations induced by IR without any change in proinflammatory cytokine levels.

CONCLUSION(S): The protective effect of melatonin on IR-induced testiculary injury is related to its antioxidant properties but not to proinflammatory cytokines.