EFFECTS OF MANGANESE AND VITAMIN-E DEFICIENCIES ON ANTIOXIDANT ENZYMES IN STREPTOZOTOCIN-DIABETIC RATS

Vitamin E and manganese deficiencies have been shown independently to affect the capacity to scavenge endogenously produced reactive oxygen species (ROS) in streptozotocin (STZ)-diabetic, Sprague-Dawley rats. W hether combined vitamin E and manganese deficiencies would additively affect oxidative stress was assessed in this study. Plasma and hepatic vitamin E were severely depleted in vitamin E-deficient rats, and sus ceptibility to lipid peroxidation in kidney, heart, liver, and pancrea s tissues was increased, independent of manganese. Activities of key a ntioxidant enzymes, including superoxide dismutase, glutathione peroxi dase, glutathione reductase, and catalase in heart, liver, kidney, and pancreas were altered by manganese and vitamin E deficiencies, althou gh no additive effects were observed. Hemoglobin glycosylation was ele vated in vitamin E-deficient, diabetic rats, an effect that further un derscores the increased oxidative stress in vitamin E deficiency state s.