The aim of this study was to monitor the effect of the administration of antihypertensive drug losartan on: (1) the antioxidant status of rats with experimental insulin-dependent diabetes mellitus; (2) oxidative damage which is represented by the production of compounds which can react with thiobarbituric acid (TBARP), and (3) some metabolic parameters. Losartan administration did not significantly influence the concentration of glucose, cholesterol, triacylglycerol, and uric acid in the plasma of control and diabetic animals. In the liver tissue, the concentration of triacylglycerols decreased after losartan administration, but the concentration of cholesterol did not change. The present authors have found that losartan administration increased the levels of water solubile antioxidants in the plasma of diabetic rats, which can result in a decrease of the TBARP levels in the plasma of diabetic rats.

        Key words: antioxidant status - losartan - diabetes mellitus - oxidative stress