An investigation into the effect of sulfonylurea glyburide on glutathione peroxidase activity in streptozotocin-induced diabetic rat muscle tissue.

1. Four weeks of glyburide (glibenclamide) treatment (5 mg/kg, orally) was administered in type II diabetic rats and the effect of such treatment was determined on muscle glutathione peroxidase (GPx) activity. 2. GPx activity was measured by a spectrophotometric method in which its activity was coupled to the oxidation of NADPH by glutathione reductase. 3. No statistically significant difference was found in muscle GPx activity between diabetic rats and controls. 4. There was a significant difference in GPx activity between glyburide-treated diabetic and nontreated diabetic groups and between glyburide-treated control and control groups. 5. The results of this study demonstrated that diabetes did not significantly alter skeletal muscle GPx activity in diabetic rats. However, glyburide may be an effective antioxidant agent in addition to its expected insulin-like effects.