Administration of a Branched-Chain Amino Acid Preparation during Hepatic Failure: A Study Emphasizing Ammonia Metabolism

We administered a branched-chain amino acid (BCAA) infusion to 16 patients with hepatic failure and two healthy subjects, and then evaluated its effects on ammonia metabolism and amino acid metabolic pool. Immediately after the BCAA infusion, the venous blood ammonia concentration increased in 12 of 15 patients with hepatic failure and in both two healthy subjects. Glutamine (Gln) also rose in all cases following the BCAA infusion, and this rise was particularly marked in the hepatic failure group. The increase in Gln due to the BCAA infusion and the arteriovenous difference in the pre-administration ammonia concentration showed a good correlation. These results suggest an increase in glutamine cycle capacity in patients with hepatic failure.