Effect of Three-week Zinc and Melatonin Supplementation on the Oxidant-antioxidant System in Experimental Renal Ischemia-reperfusion in Rats.

Renal ischemia-reperfusion directly affects glomerular and tubular epithelium. Oxygen free radicals have a significant part in the pathophysiology of renal ischemia-reperfusion injury. The present study aimed to identify the effects of 3-week zinc, melatonin, and zinc + melato- nin supplementation on malondialdehyde (MDA) levels in tissue and plasma and glutathione levels (GSH) in erythrocytes and tissue of rats with experimentally induced renal ischemia-reperfusion injury. The study included Wistar albino rats with a mean weight of 250 g. Study groups were formed as follows: control, sham-control, ischemia + reperfusion, zinc + ischemia-reperfusion, melatonin + ischemia-reperfusion, and zinc + melatonin + ischemia-reperfusion. Animals were supplemented with zinc and melatonin 3 mg/kg/day i.p. for 3 weeks before the induction of ischemia-reperfusion. Renal ischemia-reperfusion was induced in the left kidney under general anesthesia and consisted of ischemia for 45 minutes and reperfusion for 1 hour. After the procedure, animals were sacrificed and blood and kidney samples were collected to analyze MDA and GSH levels. GSH values in kidney tissues and erythrocytes were found to be elevated in the groups supplemented with zinc and melatonin (p < 0.005). When MDA values in renal tissue and plasma were examined, it was seen that ischemia significantly elevated this parameter, while zinc and melatonin supplementation signifi- cantly inhibited MDA values (p < 0.002). The results of the study indicated that oxidative injury of the blood and renal tissues of rats increased in association with ischemia-reperfusion, but zinc and melatonin supplementation before ischemia-reperfusion markedly reduced this oxidative damage.