Glutamine concentration and tissue exchange with intravenously administered alpha-ketoglutaric acid and ammonium: a dose-response study in the pig.
OBJECTIVE
We investigated the effects of an intravenous load of alpha-ketoglutaric acid, ammonium (NH(4)(+)), and metabolic acidosis on plasma concentration and splanchnic and hindleg tissue exchange of glutamine, glutamate, alanine, and arginine in postabsorptive, anesthetized pigs.


METHODS
Sixteen anesthetized piglets received a constant infusion of NH(4)Cl for 4 h and alpha-ketoglutaric acid in incremental dosages for 3 h (group 1, n = 8) or a constant infusion of alpha-ketoglutaric acid for 4 h and NH(4)Cl in incremental dosages for 3 h (group 2, n = 8). Plasma amino acids were analyzed and splanchnic blood flow was calculated according to the indocyanine green dye infusion technique. Femoral artery blood flow was measured with ultrasound flowmetry. Statistical evaluation of within-group differences was made with the Wilcoxon signed rank test.


RESULTS
Plasma glutamine levels increased dose-dependently in group 2 (P < 0.05) but not in group 1. Glutamate concentration increased, mainly in group 2 (P < 0.05), whereas the plasma concentration of alanine decreased in both groups (P < 0.05). Plasma concentration of arginine increased in both groups (P < 0.05). Splanchnic uptake and skeletal muscle release of glutamine did not change in either group compared with baseline values. Splanchnic glutamate release decreased (P < 0.05) in group 1 at 240 min; muscular uptake was unaffected in both groups. Splanchnic uptake and muscular release of alanine were unaffected in both groups. The significance level was set at 0.05.


CONCLUSIONS
Our findings indicate that the splanchnic bed or hindleg skeletal muscle was not the source of the increased plasma concentration of glutamine in this study.
Nordgren
Anders
A
Department of Surgical Sciences/Anesthesiology and Intensive Care, University Hospital, SE-751 85 Uppsala, Sweden. anders.nordgren@anestesi.uu.se
Karlsson
Torbjörn
T
Wiklund
Lars
L
D000138:Acidosis / Q000097:blood; D000409:Alanine / Q000097:blood; D000596:Amino Acids / Q000097:blood*; D000818:Animals; D001784:Blood Gas Analysis; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005260:Female; D018698:Glutamic Acid / Q000097:blood; D005973:Glutamine / Q000097:blood*; D007275:Injections, Intravenous; D007656:Ketoglutaric Acids / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D011897:Random Allocation; D013152:Splanchnic Circulation / Q000502:physiology; D013552:Swine; D014508:Urea / Q000097:blood; D014781:Viscera / Q000098:blood supply
D000596:Amino Acids; D007656:Ketoglutaric Acids; D000644:Quaternary Ammonium Compounds; D005973:Glutamine; D018698:Glutamic Acid; D014508:Urea; D000409:Alanine