Background: Cardiovascular disease including hypertension are complications of long-standing diabetes. A few Studies had shown the positive effects of L-carnitine on hypertension. In this study, the possible effects of L-carnitne on nitric oxide (NO) levels and angiotensin-converting enzyme (ACE) activity in serum as well as systolic blood pressure (SBP) in diabetic and normal rats were studied.

Methods: In this study forty rats were used in four groups including non-treated control (C), L-carnitne treated control (CT), diabetic (D) and L-carnitne treated diabetic (DT). Diabetes was induced in rats by injection of stereptozotosin. Both of C & D groups had a free access to food and water and CT & DT groups were received daily dose of L-carnation in drinking water. At the end of 12 weeks SBP, serum NO and ACE activity were measured.

Results: Systolic blood pressure was significantly decreased in DT group compared to D group. Serum ACE activity was also significantly decreased in DT group compared to D group and the serum NO levels were significantly increased in DT & CT groups compared to D & C groups respectively.

Conclusion: Finally it could be concluded that L-carnitine may reduce SBP in diabetic rats via elevation of serum NO levels and reduction of serum ACE activity.