NOS3 and Cirrhosis: Endothelial dysfunction is an important feature of cirrhosis, one that is highlighted by an impaired vasodilator response to acetylcholine, reduced production of nitric oxide (NO) by endothelial nitric oxide synthase (eNOS), as well as increased NO breakdown due to inflammation and oxidative stress.120, 121This then leads to impaired endothelial relaxation in the hepatic microcirculation contributing to increased intrahepatic vascular resistance.122On the other hand, in the splanchnic vessels, overproduction of NO leads to vasodilation and hyperdynamic vascular disturbances.18