AJP - Endocrinology and Metabolism, Vol 250, Issue 6 622-E628, Copyright © 1986 by American Physiological Society

ARTICLES

Role of glutamine in adaptations in nitrogen metabolism during fasting

E. Cersosimo, P. E. Williams, P. M. Radosevich, B. T. Hoxworth, W. W. Lacy and N. N. Abumrad

The present study examines the effect of glutamine infusion on the interorgan fluxes of glutamine, alanine, urea, and ammonia with progressive fasting. Experiments were carried out in two groups of conscious dogs with catheters previously implanted in an artery and in the hepatic, portal, and renal veins. Group I (n = 12) was fasted for 24 h, and group II (n = 10) was fasted for 96 h. On the day of the study, seven animals of group I and five of group II received a constant infusion of glutamine (3.0 mumol . kg-1 . min-1) for 1 h, and the rest (controls) received saline. Four-day fasting produced ketosis with a compensated metabolic acidosis. The demand for glutamine by the kidneys and gut increased, and the liver switched from net glutamine utilization to that of net production. The kidneys (33%) and gut (230%) increased their production of ammonia, while their release of alanine decreased. The estimated efflux of glutamine by skeletal muscle, however, did not change. All of the infused glutamine was cleared by the splanchnic and renal tissues. In group I, there was increased gut production of alanine, which was matched by increased hepatic alanine uptake and urea production. No such changes were observed in Group II. There was, however, an increase in hepatic uptake of ammonia. Finally, glutamine infusion did not alter glutamine or alanine output by skeletal muscle in group I, while it decreased efflux of alanine but not that of glutamine in group II. The data emphasize the complex interdependence of the liver, gut, kidneys, and skeletal muscle in nitrogen sparing.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				D. S. C. Raj, T. Welbourne, E. A. Dominic, D. Waters, R. Wolfe, and A. Ferrando Glutamine kinetics and protein turnover in end-stage renal disease Am J Physiol Endocrinol Metab, January 1, 2005; 288(1): E37 - E46. [Abstract] [Full Text] [PDF]

				G. Mithieux, I. Bady, A. Gautier, M. Croset, F. Rajas, and C. Zitoun Induction of control genes in intestinal gluconeogenesis is sequential during fasting and maximal in diabetes Am J Physiol Endocrinol Metab, March 1, 2004; 286(3): E370 - E375. [Abstract] [Full Text]

				M Plauth, A-E Roske, P Romaniuk, E Roth, R Ziebig, and H Lochs Post-feeding hyperammonaemia in patients with transjugular intrahepatic portosystemic shunt and liver cirrhosis: role of small intestinal ammonia release and route of nutrient administration Gut, June 1, 2000; 46(6): 849 - 855. [Abstract] [Full Text] [PDF]

				M. Watford Glutamine and Glutamate Metabolism across the Liver Sinusoid J. Nutr., April 1, 2000; 130(4): 983 - 983. [Abstract] [Full Text]

				J. S. Marchini, P. Nguyen, J.-Y. Deschamps, P. Maugere, M. Krempf, and D. Darmaun Effect of intravenous glutamine on duodenal mucosa protein synthesis in healthy growing dogs Am J Physiol Endocrinol Metab, April 1, 1999; 276(4): E747 - E753. [Abstract] [Full Text] [PDF]