Endothelial Dysfunction in Distributive Shock

Abstract

Since the 1990s, nitric oxide (NO) has been associated with vasoplegia of septic shock resistant to high doses of catecholamines. After exposure to bacterial endotoxin or specific cytokines, the inducible nitric oxide synthase (iNOS) expression occurs in a wide variety of tissues. This enzyme produces large NO amounts over long periods, closely related to the pathophysiological changes in sepsis. NO synthesis inhibitors can reverse hypotension caused by endotoxin and cytokine, and these agents could, in theory, constitute a modern therapeutic approach to severe septic shock. Preliminary studies in humans suggest that NOS inhibition improves blood pressure and stabilizes hemodynamics, but mortality rates remain undetermined. It can be said that the use of synthesis inhibitors was associated with increased mortality compared to the control group in humans, causing multicenter studies to be interrupted. The participation of the overproduction of NO by the iNOS expression is evident, leading to a vasoplegia state that is irresponsible to high doses of catecholamines. Since guanylate cyclase is the endothelium-dependent relaxation enzyme, MB is a potent inhibitor of this enzyme and an essential option for the vasoplegia in sepsis treatment.