Amino acid concentration in plasma after gastro-intestinal, intraportal and intravenous administration of glutamic acid.
Three groups of dogs with two dogs in each group were given a solution of glutamic acid by three different routes: gastrointestinally, intraportally and intravenously. Free plasma amino acid concentrations were determined in arterial blood and peripheral, portal and hepatic venous blood. Blood sampling was performed before, during and after the two-hour infusion period. Most amino acids did not change in plasma concentration during the experiment. Glutamic acid increased to very high concentration levels during parenteral infusion but also during gastro-intestinal ingestion in spite of the known metabolism of that amino acid in the intestinal mucosa. Alanine, which is known to originate in the mucosa from transaminated glutamic acid, increased more in portal venous blood in the gastro-intestinal group than in the other two groups. Plasma alanine levels were higher in peripheral venous blood than in any other blood vessel, when the glutamic acid infusion was administered parenterally, indicating a peripheral alanine production rather than an intestinal release. Glutamine decreased slightly during the infusions by all three routes and showed a tendency to increase after ending the infusions. There was also a tendency towards an increase in the branched chain amino acids throughout the experimental period in all three groups.
D000284:Administration, Oral; D000409:Alanine / Q000097:blood*; D000818:Animals; D004285:Dogs; D005971:Glutamates / Q000008:administration & dosage* / Q000378:metabolism; D005973:Glutamine / Q000097:blood*; D007263:Infusions, Parenteral; D014508:Urea / Q000097:blood
D005971:Glutamates; D005973:Glutamine; D014508:Urea; D000409:Alanine