Beneficial effects of levo-carnitine on lipid metabolism and cardiac function in neonatal streptozotocin rat model of diabetes

Abstract

Levo-carnitine (L-carnitine) facilitates the transport of long chain fatty acyl co-enzyme A (CoA) across the mitochondrial membrane for eventual oxidation and energy production. Carnitine deficiency results in free fatty acid accumulation and contributes to cardiovascular complications in experimental diabetes. In this condition, oral carnitine supplementation provides cardio-protection by its various metabolic effects. The beneficial effects of six weeks treatment with L-carnitine (600 mg/kg day orally) were studied in neonatal streptozotocin (STZ) diabetic rats. STZ (90 mg/kg) was administered to five day old rats and after fourteen weeks of STZ administration, the rats showed hyperglycemia, hyperinsulinemia, hypercholesterolemia, hypertriglyceridemia and associated cardiac defects like hypertension and bradycardia. L-carnitine treatment for six weeks after induction of diabetes and associated complications significantly lowered cholesterol and triglyceride levels and normalized blood pressure and heart rate; however the treatment was not found to produce beneficial effects against hyperglycemia and hyperinsulinemia in diabetic rats. The L-carnitine treatment may have fulfilled the carnitine deficiency and have improved the lipid metabolism and subsequently the cardiac function in diabetic rats. The study suggest that long term treatment with L-carnitine not only prevents but also partially reverses the diabetes-associated lipid metabolism and cardiac function abnormalities in neonatal STZ diabetic rats.