Objectives: The serum nitrate concentration is known to be increased in patients with cirrhosis. This study was designed to determine the kinetics of nitrate in the splanchnic vascular areas and its relationship with hepatic hemodynamics in patients with compensated cirrhosis.
Methods: We measured the serum nitrate concentration of various sites, including the femoral artery, hepatic vein, azygos vein, and pulmonary artery, and compared these values with hepatic hemodynamics.
Results: The nitrate concentrations of hepatic vein and azygos vein were significantly greater in cirrhotic patients compared with those of control subjects. The values were particularly elevated in patients with Child-Pugh's class B. In control subjects, hepatic vein and azygos vein nitrate concentrations were significantly lower than arterial nitrate concentrations whereas nitrate concentrations were significantly greater in the hepatic and azygos veins than femoral artery in cirrhotic patients, and nitrate kinetics was that of the net release of nitrate from the hepatic and azygos veins. The portal vein blood flow positively correlated with the nitrate concentration of azygos vein, pulmonary artery, and femoral artery.
Conclusions: The present results implicate the enhanced production of nitric oxide in the mesenteric vascular beds in patients with cirrhosis. The positive correlation between portal vein blood flow and serum nitrate concentrations suggests that endogenous nitric oxide may have an important role in the regulation of portal hemodynamics in these patients.