Mechanisms of the Endothelium-Dependent Relaxation Induced by NG-Hydroxy-L-Arginine

There are three mechanisms by which N G -hydroxy-L-arginine (L-HOArg) induces endothelium-dependent relaxations. L-HOArg is a substrate for the constitutive nitric oxide (NO) synthase present in endothelial cells (ECs). It reacts with NO released from EC to form a potent and more stable vasodilator. Moreover, it induces a relatively stable, EC-dependent relaxation that is not blocked by the inhibitors of NO synthesis. Subsequently, we have investigated the effects of hydroxyguanidine (HOG) on the biological activity of endothelium-derived relaxing factor (EDRF)