Plasma glucagon concentration in cirrhosis is related to liver function but not to portal-systemic shunting, systemic vascular resistance, or urinary sodium excretion. We tested the hypothesis that increased plasma glucagon concentration resulting from portal-systemic shunting or liver dysfunction causes arterial vasodilation and thereby stimulates sodium retention in cirrhosis. Twenty-seven studies were performed in patients with alcoholic liver disease, 11 of whom had ascites. Liver function was quantitated as the elimination rate of antipyrine, caffeine, and stable isotopes of cholic acid administered both orally (2,2,4,4-2H) and intravenously (24-13C). Portal-systemic shunt fraction was calculated as the ratio of the intravenous and oral clearances of the isotopes of cholic acid. Cardiac output was measured by using Doppler echocardiography. Plasma glucagon concentration was increased in patients with ascites when compared with that in patients without ascites (474 +/- 180 pg/ml vs 245 +/- 120 pg/ml, p = 0.0007) but was unrelated to urinary sodium excretion, heart rate, mean arterial pressure, cardiac output, and systemic vascular resistance (r = -0.48, 0.35, -0.13, 0.18, and 0.22, respectively). Plasma glucagon concentration correlated with the half-lives of all model compounds (r = 0.58, p = 0.002; r = 0.62, p = 0.0008; r = 0.62, p = 0.001; and r = 0.64, p = 0.0005; for caffeine, antipyrine, oral and intravenous cholic acid, respectively) but not with shunt fraction (r = 0.14). Increased plasma glucagon concentration in cirrhosis is probably a result of diminished hepatic clearance. However, increased plasma concentration of glucagon does not appear to cause a hyperdynamic circulatory state or sodium retention. 