[Clinical study on the concentration of free amino acids in plasma and urine during postaggression metabolism. I].

We studied the changes in the concentration pattern of free plasma amino acids in 30 surgical patients during standardized parenteral nutrition and exclusive water and electrolyte supply. Distinct reproducible differences were found in comparison to normal subjects. The concentration of branched-chain amino acids continuously increases during the post-operative period. The decrease of alanine is closely related. Phenylalanine also increases continuously due to insufficient transformation in the liver and increased release from the muscles. During post-aggression metabolism, cystine is probably not sufficiently formed from methionine and should be substituted. It may be that tyrosine is also essential for patients in the post-operative post-traumatic period. The glycine concentration of some amino acid mixtures is regarded as too high; the glycine content can be reduced in favour of serine supply.