Vasoactive Substances in Portal Hypertension

Abstract

Hypercirculatory state in the splanchnic organs is associated with chronic portal hypertension as human liver cirrhosis. Vasoactive substances such as nitric oxide (NO), prostaglandins, endothelium-derived hyperpolarizing factor (EDHF) are the candidates which mediate the hypercirculatory state. In stomach, dilatation of the mucosal capillaries and submucosal vessels (human), and increase (rat) or increase/decrease (human) in the blood flow have been reported. Hypocirculatory state in the stomach is associated with acute portal hypertension. Decrease of the gastric blood flow with mucosal congestion and contriction of the submucosal arterioles and venules is seen. NO and endothelin (ET) produced locally are involved in the change of the arterioles and the predominant function of ET constricts the arterioles.