Effect of L-Carnitine on Endothelial Dysfunction markers in Diabetic-Irradiated rats

Dimethylarginine (ADMA), endothelin-1(ET-1) and total nitrate/nitrite (NO(x)) are mediators of endothelial dysfunction and involved in the pathogenesis of cardiovascular diseases. Diabetes and γ-irradiation (IRR) exposure are associated with the development of various cardiovascular diseases. Oxidative stress plays a major role in the pathogenesis of diabetes mellitus leading to various complications including endothelial dysfunction. The present study was designed to evaluate the effect of L-carnitine (L-car) on ADMA, endothelin-1 and NO(x) in diabetic-γ-irradiated (STZ-IRR)rat and evaluate the anti-hyperglycemic properties of L-carnitine on streptozotocin (STZ)-induced diabetes. Serum lipid profiles, glucose level, ADMA, ET-1 and NO(x) were determined. The cellular changes were estimated using malondialdehyde (MDA) as indicies of lipid peroxidation, the antioxidants superoxide dismutase (SOD), glutathione peroxidase (GSHPx) and reduced glutathione (GSH) and NO(x). Circulatory lipid profiles, ADMA, endothelin-1 and cardiac MDA were increased significantly, whereas the level of serum NO(x) and cardiac GSH and antioxidant enzymes were significantly decreased in IRR (5 Gy), STZ and STZ-IRRrats. Treatment with L-carnitine (200 mg/kg, i.p., every other day) for 28 days, resulted in a significant decrease in the levels of blood glucose and lipid profiles along with a significant decrease in the levels of serum ADMA,endothelin-1 and cardiac MDA. The cardiac antioxidant enzymes and GSH were increased significantly along with the serum NO(x).In conclusion, ADMA, endothelin-1 and NO(x) were implicated in endothelial dysfunction of rats exposed to STZ and/or gamma-radiation.L-carnitineoffers promising radioprotective and antidiabetic effects that may be mainly attributed to its potent antioxidant. © 2013 Universal Research Publications. All rights reserved.