title: Hepato-systemic gradient of carbon monoxide in cirrhosis.
abstract: OBJECTIVE
  Experimental data suggest that in liver cirrhosis splanchnic and systemic vasculature exhibit marked endothelial Carbon monoxide (CO) overproduction, while recent data demonstrated heme oxygenase (HO) hyperactivity in the liver of rats with cirrhosis. No data are so far available on CO levels in the hepatic veins of cirrhotic patients. We aimed at evaluating whether plasma CO levels differ between systemic (peripheral vein) and hepatic (hepatic vein) circulation in patients with viral cirrhosis with and without ascites.
  
  
  METHODS
  We enrolled 31 consecutive non-smoking in- or outpatients with liver cirrhosis. We measured wedge (occluded, WHVP) and free hepatic venous pressures (FHVP) and hepatic-vein pressure gradient (HVPG) was the calculated. Plasma level of NO and plasma CO concentration were determined both in peripheral vein and in the hepatic vein in cirrhotics.
  
  
  RESULTS
  In cirrhotic patients plasma CO levels were significantly higher in the hepatic vein (16.66±10.71 p.p.m.) than in the peripheral vein (11.71±7.00 p.p.m). Plasma NO levels were significantly higher in peripheral vein (97.02±21.11 μmol/ml) than in the hepatic vein (60.76±22.93 μmol/ml).
  
  
  CONCLUSIONS
  In patients with liver cirrhosis we documented a hepato-systemic CO gradient as inferred by the higher CO values in the hepatic vein than in the peripheral vein. In cirrhotic patients, CO and NO exhibit opposite behavior in the liver, while both molecules show increased values in the systemic circulation. It can be speculated that increased intra-hepatic CO levels might represent a counterbalancing response to reduced NO intra-hepatic levels in human liver cirrhosis.
authors.affiliation: Department of Internal Medicine, University of Florence, School of Medicine, 50134 Florence, Italy. rtarquini@unifi.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Tarquini
authors.forename: Emanuela
authors.initials: E
authors.lastname: Masini
authors.forename: Giorgio
authors.initials: G
authors.lastname: La Villa
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Mazzoccoli
authors.forename: Rosanna
authors.initials: R
authors.lastname: Mastroianni
authors.forename: Roberto Giulio
authors.initials: RG
authors.lastname: Romanelli
authors.forename: Francesco
authors.initials: F
authors.lastname: Vizzutti
authors.forename: Umberto
authors.initials: U
authors.lastname: Arena
authors.forename: Ugo
authors.initials: U
authors.lastname: Santosuosso
authors.forename: Giacomo
authors.initials: G
authors.lastname: Laffi
mesh_terms: D002248:Carbon Monoxide / Q000097:blood*; D005260:Female; D006503:Hepatic Veins; D006801:Humans; D008103:Liver Cirrhosis / Q000097:blood*; D008297:Male; D008875:Middle Aged
chemical_list: D002248:Carbon Monoxide