Basic knowledge of interest

Journal of Hepato-Biliary-Pancreatic Surgery

, Volume 3, Issue 2, pp 154-160

First online:

Superoxide, NO and CO in liver microcirculation: Physiology and pathophysiology

  • Makoto SuematsuAffiliated withDepartment of Biochemistry, School of Medicine, Keio University
  • , Yusuke KumamotoAffiliated withDepartment of Biochemistry, School of Medicine, Keio University
  • , Tsuyoshi SanoAffiliated withDepartment of Biochemistry, School of Medicine, Keio University
  • , Yoshiyuki WakabayashiAffiliated withDepartment of Biochemistry, School of Medicine, Keio University
  • , Yuzuru IshimuraAffiliated withDepartment of Biochemistry, School of Medicine, Keio University

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Superoxide anion (O2 ), nitric oxide (NO), and carbon monoxide (CO) are metabolites of molecular oxygen endogenously generated through oxygen activation by a variety of oxidases and oxygenases such as xanthine oxidase and NADPH oxidase, NO synthase, and heme oxygenase, respectively. There is an increasing body of evidence showing that these active oxygen metabolites not only exert their cytotoxic properties but also play a modulatory role in regulation of cell function in and around hepatic sinusoidal vessels. Among them, CO generated by heme oxygenase is a novel vasodilatory mediator which can upregulate cGMP in fatstoring Ito cells, liver-specific microvascular pericytes which encircle sinusoidal walls, and thereby control the microvascular tone under control conditions. When exposed to endotoxemia, Kupffer cells and hepatocytes can express inducible NO synthase activity which serves as a NO-dependent cytotoxic mechanisms involving peroxynitrite formation. Disclosure of the whole picture of NO- and CO-dependent mechanisms for regulation of hepatic microcirculation gives a clue to understanding the physiology and pathophysiology of liver function.

Key words

nitric oxide carbon monoxide oxidative stress Ito cells sinusoids