Plasma and Brain Amino Acids in Fulminant Hepatic Failure and their Relationship to Hepatic Encephalopathy
Article first published online: 28 JUN 2008
European Journal of Clinical Investigation
Volume 6, Issue 1, pages 387–394, February 1976
How to Cite
Record, C. O., Buxton, B., Chase, R. A., Curzon, G., Murray-Lyon, I. M. and Williams, R. (1976), Plasma and Brain Amino Acids in Fulminant Hepatic Failure and their Relationship to Hepatic Encephalopathy. European Journal of Clinical Investigation, 6: 387–394. doi: 10.1111/j.1365-2362.1976.tb00533.x
- Issue published online: 28 JUN 2008
- Article first published online: 28 JUN 2008
- August 26, 1975 February 26, 1976
- Fulminant hepatic failure;
- Amino acids;
- Hepatic encephalopathy;
- Brain tryptophan;
- Neurotransmitter metabolism
Amino acid concentrations were determined in plasma, whole blood, cerebrospinal fluid and brain tissue of 45 patients with grade 3 or 4 coma due to fulminant hepatic failure. The concentration of 15 of the 19 amino acids determined were significantly increased in blood and the, increases were greatest for the amino acids concerned with neurotransmitter metabolism. There was no correlation, however, between the plasma concentration of these amino acids and changes in the grade of hepatic coma. The plasma concentrations of the branched chain amino acids were normal except in those patients who subsequently recovered in whom levels were slightly decreased.
Phenylalanine, tyrosine and methionine were among the 15 out of 18 amino acids which were significantly increased in cerebrospinal fluid and among the 15 out of 21 amino acids which were significantly increased in the brain. The increase in tryptophan was associated with a significant elevation in brain 5-hyroxyindoleacetic acid concentration suggesting an increase in 5-hydroxytryptamine turnover in hepatic coma.
Brain to plasma ratios of most amino acids in hepatic coma patients were similar to control subjects suggesting that plasma concentration is the main factor controlling the cerebral concentration. However, for the branched chain amino acids, cerebrospinal fluid and brain concentrations were increased when plasma concentrations were normal suggesting an increase in brain uptake.