Influence of alanylglutamine infusion on gastrointestinal glutamine and alanine metabolism in anesthetized dogs.
In this study we administered an infusion of alanylglutamine (10 mumol/kg.min) for 60 minutes to postoperative anaesthetized dogs with catheters placed in the portal and hepatic veins. Arterial plasma levels of alanylglutamine were 83 +/- 27 mumol/L 20 minutes after the onset of the infusion and remained constant throughout the infusion period. Plasma levels of glutamine and alanine approximately doubled compared with preinfusion levels, indicating a release of these amino acids from the dipeptide. The halflife of alanylglutamine, calculated after bolus injection of 2 g, was 1.7 +/- 0.5 minutes. Alanylglutamine was extracted from the liver and the gut (0.9 +/- 0.3 and 0.5 +/- 0.1 mumol/kg.min, respectively). In the basal period (without infusion of alanylglutamine), a glutamine uptake by the liver and the intestine was found. Alanine was taken up by the liver and released from the gut. The infusion of alanylglutamine significantly increased the hepatic uptake of glutamine and alanine (from 0.8 +/- 0.2 to 3.8 +/- 0.6 and from 3.0 +/- 0.4 to 7.5 +/- 0.7 mumol/kg.min respectively; P less than .01) and did not significantly change the intestinal uptake of glutamine and the release of alanine. We conclude that the infusion of alanylglutamine markedly influences the hepatic metabolism of glutamine and alanine, probably via the increased arterial and portal levels of glutamine and alanine.
First Surgical University Clinic, Department of Surgical Pathophysiology, Vienna, Austria.
J
J
Karner
E
E
Roth
D000409:Alanine / Q000097:blood / Q000378:metabolism*; D000818:Animals; D001158:Arteries; D004064:Digestive System / Q000187:drug effects / Q000378:metabolism*; D004151:Dipeptides / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D004285:Dogs; D005260:Female; D005973:Glutamine / Q000097:blood / Q000378:metabolism*; D006207:Half-Life; D006499:Hepatic Artery; D007262:Infusions, Intravenous; D007413:Intestinal Mucosa / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008102:Liver Circulation; D008297:Male; D011169:Portal Vein
D004151:Dipeptides; D005973:Glutamine; D000409:Alanine; C054122:alanylglutamine