Clinical and Experimental Hypertension

Recent evidence suggests that impaired antioxidant status is involved in oxidative stress associated with diabetes. The main antioxidant enzymes include superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). The aim of the present investigation was to evaluate the activities and protein expression of these antioxidant enzymes in streptozotocin-induced diabetes. Furthermore, the effects of insulin and antioxidant therapy alone and in combination were studied. Male SpragueDawley rats were rendered diabetic by streptozotocin administration and randomly assigned to untreated, insulin-treated, antioxidant (vitamin E and C)-treated and insulin plus antioxidant-treated groups. Normal rats fed either a regular diet or the antioxidant (vitamin E and C)-rich diet served as controls. The animals were observed for 4 weeks. Diabetic animals showed marked weight loss, decreased activities of Cu Zn SOD and CAT and normal GPX activity. Additionally, the expression of all *Correspondence: Ram K. Sindhu, Ph.D., Division of Nephrology and Hypertension, Department of Medicine, University of California, Irvine, CA 92697-4066, USA; Fax: (949) 824-5639; E-mail: [email protected]. Currrent address: Ja-Ryung Koo, Department of Medicine, Chunchon Sacred Heart Hospital, Hallym University, Kyo-Dong, Chunchon, Kangwon-Do, South Korea. zCurrrent address: Christian K. Roberts, Division of Endocrinology, Metabolism and Molecular Medicine, Charles R. Drew University of Medicine and Science, Los Angeles, California, USA.