TRAUMATIC SHOCK XVI: AMINO ACID METABOLISM IN HEMORRHAGIC SHOCK IN THE DOG

Abstract

Blood disappearance curves for many injected amino acids, singly or in a mixture, were obtained in dogs in the normal state, in hemorrhagic shock, and following transfusion. The amino acids studied individually were glycine, alanine, cysteine, lysine, tyrosine, tryptophane and aspartic acid. Normally the injd. amino acids were cleared from the blood within 1 hr. in nearly all instances. In hemorrhagic shock some, although not all, dogs showed poor clearance of certain amino acids. Following transfusion clearance was nearly normal in most cases even when circulatory collapse reappeared. There was no correlation between amino acid clearance or blood amino N concn. and reversibility to transfusion. Rises in blood urea following amino acid injn. were observed in some normal dogs and in some shocked animals. The spontaneous rise in total amino acid N usually seen as shock progressed seemed less in dogs which had received cysteine, lysine, or tyrosine. Even when blood amino N clearance was good in any phase of shock, the increase in total blood amino acid concn. persisted. The injn. of large doses of an amino acid mixture resulted in considerable clearance of the blood of the injd. amino acids without an equivalent rise in blood urea N. This would suggest protein synthesis even in dogs in shock. Evidence is presented to show that slower clearance of injected amino acids during the olig-emic phase of shock is due to deficient blood flow and not necessarily to damage to deaminase systems. The ability to clear the blood of injd. amino acid was not found to bear a significant relationship to the effectiveness of transfusion or to death or survival.