Oxidative stress in the testis of hyperglycemic rabbits treated with repaglinide

In the present study, the induction of oxidative stress was examined in the testis of alloxan-induced diabetic rabbits. In addition, the protective effect of repaglinide, an oral anti-diabetic, at a dose of 1 mg daily was studied after four and eight weeks of the treatment. For these purposes, the levels of superoxide dismutase (Cu,Zn-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R), glutathione (GSH), ascorbic acid (AA), lipid peroxidation products (LPO) and protein carbonyl groups (PCG) were quantified. Hyperglycemia resulted in significant increases in the antioxidative enzymes, Cu, Zn-SOD, CAT, GSH-Px, and GSSG-R after four and eight weeks, respectively. There was also an increase in GSH level, and a decrease in the level of AA. These effects were accompanied by an elevation in testicular LPO levels and PCG levels. Repaglinide was found to normalize the activity of GSSG-R and levels of GSH and AA, and blunted the increased lipid peroxidation, however no decrease in PCG levels were observed. In conclusion, some oxidative changes provoked in the testis of rabbits by hyperglycemia, were found to be reduced with repaglinide treatment at therapeutic dose.