ABSTRACT
BACKGROUND: Nitric Oxide (NO) induced by NO synthase is known to be associated with hyperdynamic circulation and collateralization by vascular remodeling in patients with cirrhosis. METHODS: To assess the significance of peripheral NO activity in patients with cirrhosis, we measured the production of NO metabolites, nitrate and nitrite, using the nitrate/nitrite colorimetric assay with Griess reagents in the peripheral venous blood of 95 cirrhotic patients with or without clinical portal hypertension (PHT), and in the peripheral venous blood of 32 control patients without liver disease. RESULTS: The peripheral NO activities in cirrhotic patients with clinical PHT, cirrhotic patients without clinical PHT, and non-liver disease control patients were 86.1+/-40.6 micro mol/L, 83.5+/-47.2 micro mol/L and 52.3+/-38.4 micro mol/L, respectively. NO activity was significantly higher in cirrhotic patients than in non-liver disease control patients (p<0.05), while there was no significant difference of NO activity between the cirrhotic patients with or without clinical PHT. Peripheral NO activities in cirrhotic patients with Child-Pugh classification A, B, and C were 84.9+/-45.5 micro mol/L, 81.9+/-53.2 micro mol/L and 86.4+/-39.8 micro mol/L, respectively; these results were not significantly different. A significant correlation of NO activity with the biochemical profiles of the serum albumin level, bilirubin level and prothrombin time were not defined. CONCLUSIONS: Peripheral NO activity was increased in cirrhotic patients, but it did not reflect the degree of clinical portal hypertension and the function of the hepatic reserve in this study. For a precise analysis of the association of NO and hyperdynamic circulation with collateralization in cirrhosis, intrahepatic or portal NO activity might be considered rather than peripheral NO activity.