Effects of l-arginine on endothelial and cardiac function in rats with heart failure

Abstract

We examined the effects of chronic oral l-arginine treatment on endothelial and cardiovascular function in rats with heart failure induced by coronary artery ligation. Both heart failure and sham-operated rats were treated with either l-arginine in drinking water (12.5 or 50 g/l) or water placebo for 8 weeks following surgery. Plasma l-arginine levels in heart failure rats (153±11 μM) were lower than sham rats (201±13 μM, P<0.05). The lower dose l-arginine treatment improved endothelium-dependent relaxation of isolated aortic rings of heart failure rats, while the higher dose of l-arginine treatment did not. Neither low nor high dose of l-arginine treatment improved hemodynamic parameters in heart failure rats. Thus, chronic oral l-arginine treatment at a dose of 12.5 g/l in drinking water improves endothelium-dependent relaxation, but fails to improve in vivo cardiac function in rats with heart failure.