Branched chain amino acids in heptatic encephalopathy

Background: Early theories or hepatic encephalopathy focused on ammonia-driven disruption of the Krebs cycle and cellular energy production. The “false-neurotransmitter” theory directed attention toward the interactions of amino acids, metabolism, the blood-brain barrier and neurotransmission. As they evolved, these studies revealed surprising and subtle effects of ammonia on brain amino acid uptake. Data Sources: Research over a 15-year period in Josef E. Fischer’s laboratory explored many aspects of these interactions. Subsequent studies by others have confirmed and extended them into other areas. Insights from this work continue to stimulate attempts to confirm or disprove the clinical utility of branched chain amino acids. Conclusions: Increased understanding of the factors affecting ammonia, amino acid and neurotransmitter disturbances in chronic liver failure have made a significant and ongoing contribution to the study of metabolism in health and disease.