Lipid peroxidation and antioxidant status in experimental diabetes.

ABSTRACT

Oxidative stress is currently suggested as a mechanism underlying diabetes. The present study was designed to evaluate the oxidative stress related parameters in streptozotocin-induced diabetes in rats using different complementary approaches susceptibility to in vitro oxidation (lipid peroxidation induction in liver homogenate, red blood cells hemolysis), blood antioxidant status (total antioxidant capacity by two approaches), and plasma isoprostane measurement, a new marker of lipid peroxidation in vivo. We have shown that induced liver thiobarbituric acid reactive substances increased after 4 weeks of diabetes, in spite of increased liver vitamin E content. Red blood cells hemolysis was significantly delayed after 4 weeks of diabetes. Plasma antioxidant capacity (AOC) tended to increase after 4 weeks of diabetes and was correlated with plasma vitamin E levels. Total antioxidant activity (TAA) significantly decreased after 1 week and a significant correlation was observed with plasma albumin levels. Plasma isoprostane (8-epiprostaglandinF2alpha) concentrations were not modified significantly 1 week or 4 weeks after the induction of diabetes. Levels of vitamin E in the diet and changes in its distribution among the body seems to play an important role in the development of oxidative stress during diabetes and its consequences.