ASCORBIC-ACID SUPPLEMENTATION PREVENTS HYPERLIPIDEMIA AND IMPROVES MYOCARDIAL PERFORMANCE IN STREPTOZOTOCIN-DIABETIC RATS

The present study investigated the effects of ascorbic acid (AA) suppl ementation on the cardiac performance and the plasma levels of glucose , insulin, triglycerides, cholesterol and free fatty acid in diabetic and non-diabetic rats. Diabetes was induced by intravenous injection o f streptozotocin (STZ) 55 mg/kg. AA was given in drinking water in con centrations of 1 g/l or 2 g/l for 8 weeks after STZ injection. Myocard ial performance was determined using the isolated perfused working hea rt preparations. Following AA supplementation, there were no significa nt changes in any of the parameters measured in non-diabetic rats; how ever, the occurrence of polydipsia, hyperphagia, hyperlipidemia and my ocardial dysfunction in STZ-diabetic rats was significantly alleviated in a dose-dependent manner. Nevertheless, the decreased body weight g ain, hypoinsulinemia and hyperglycemia in diabetic animals were not af fected. The data show that AA supplementation in STZ-diabetic rats imp roves both hyperlipidemia and cardiac function. However, the mechanism s of these effects and the correlation between these improvements are not dear.