Enteral glutamine modulates renal glutamine utilization
Welbourne, T.; Mu, X.; Evans, S.
Journal of Nutrition 126(4 Suppl): 1137s-1141s
1996
ISSN/ISBN: 0022-3166 PMID: 8642446 Document Number: 467682
Enteral glutamine feeding effect on renal glutamine utilization was assessed from the perspective of gamma glutamyltransferase activity-dependent cellular glutamate modulation of phosphate-dependent glutaminase. After 4 d, rats fed an elemental diet supplemented with glutamine exhibited a 21% higher kidney glutamate content and 27% reduction in ammonium excretion, both P lt 0.05. Glutamine removal from plasma was depressed 62% in the glutamine-fed group (324 +- 155 vs. 780 +- 154 nmol cntdot min-1 cntdot 100 g body weight-1, P lt 0.05) despite an elevated arterial plasma glutamine load delivered to the kidney. Administration of acivicin, 36 mg/kg body weight, to glutamine-fed rats inhibited gamma glutamyltransferase gt 90% and decreased kidney glutamate content 42%. This reduction in kidney glutamate was associated with a 3.3-fold enhancement in both glutamine extraction (474 +- 184 to 1548 +- 255 nmol cntdot min-1 cntdot 100 g body weight-1) and ammonium excretion (295 +- 30 to 978 +- 96 nmol cntdot min-1 cntdot 100 g body weight-1), both P lt 0.01. These findings are consistent with enteral glutamine regulation of renal glutamine utilization through an elevation of the cellular glutamate level.