In order to investigate disturbances in glycoregulation and plasma amino acids and their possible relationship in alcoholic liver diseases, plasma concentrations of insulin, C-peptide, glucagon and branched-chain (valine, leucine, isoleucine) as well as aromatic (phenylalanine, tyrosine) amino acids were measured during an arginine test (i.v infusion of arginine chloride 0.5 g/kg over 30 min) in 21 alcoholic patients: 11 with cirrhosis (group C) and 10 with steatosis (group S). Insulin responses to arginine was reduced in both groups, whereas glucagon response was increased in group C and reduced in group S. Plasma concentrations of branched-chain amino acids were reduced in both groups, irrespective of the degree of hyperinsulinism. Plasma concentrations of aromatic amino acids were increased only in cirrhotic patients; the increase was independent of the degree of hyperglucagonism and of the plasma insulin/glucagon molar ratio. These results suggest that disturbances of glycoregulation in plasma amino acids imbalance do not play a major role in alcoholic cirrhosis and steatosis.