Effect of different vitamin E levels on lipid peroxidation in streptozotocin-diabetic rats

Administration of streptozotocin is used to induce diabetes in experimental models, causing a selective destruction of pancreatic beta islet cells ass ociated with generation of free radicals. Supplementation with antioxidant vitamins such as vitamin E is a protective factor against free radicals. Th e objective of this study was to determine the effect of administration of a diet supplemented with, or deficient in vitamin E to streptozotocin diabe tic rats, controlled or not with insulin, on plasma glucose, hepatic vitami n E and hepatic thiobarbituric acid reactive substance (TBARS) levels befor e streptozotocin and 24 hours and one and two weeks after drug administrati on. Deficiency of vitamin E alone increased TEARS levels, and streptozotoci n elevated TEARS two times in deficient groups, regardless of insulin contr ol, In rats supplemented with vitamin E, a reduction of plas ma glucose and liver vitamin E was observed two weeks after streptozotocin administration (p < 0.05). In conclusion, vitamin E supplementation probably protected ag ainst lipoperoxidation and contributed to the absence of elevation of plasm a glucose levels, and vitamin E deficiency produced an increase in hepatic TEARS levels in streptozotocin diabetic rats.