Protein restriction and dexamethasone as a model of protein hypercatabolism in dogs: Effect of glutamine on leucine turnover

To determine (1) whether protein restriction, combined with glucocorticosteroid treatment, can be used as a hypercatabolic model and (2) if so, whether glutamine attenuates protein wasting in this model, the effects of protein restriction, dexamethasone, and glutamine on leucine metabolism were asse...

Full description

Saved in:
Bibliographic Details
Published in:Metabolism, clinical and experimental clinical and experimental, 2001-03, Vol.50 (3), p.293-298
Main Authors: Humbert, Bernard, Le Bacquer, Olivier, Nguyen, Patrick, Dumon, Henri, Darmaun, Dominique
Format: Article
Language:English
Subjects:
Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy
Animals
Biological and medical sciences
Dexamethasone
Dietary Proteins - administration & dosage
Dogs
Emergency and intensive care: metabolism and nutrition disorders. Enteral and parenteral nutrition
Glucocorticoids
Glutamine - pharmacology
Injections, Intravenous
Intensive care medicine
Kinetics
Leucine - metabolism
Medical sciences
Metabolic Diseases - chemically induced
Metabolic Diseases - etiology
Oxidation-Reduction - drug effects
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:To determine (1) whether protein restriction, combined with glucocorticosteroid treatment, can be used as a hypercatabolic model and (2) if so, whether glutamine attenuates protein wasting in this model, the effects of protein restriction, dexamethasone, and glutamine on leucine metabolism were assessed in dogs. A control group (n = 8) received a maintenance diet; another group (n = 8) received a protein-restricted diet either (1) alone; (2) along with a 7-day corticoid treatment; or (3) along with a 7-day corticoid treatment and a 7-hour intravenous (IV) glutamine infusion. The last day of each regimen, dogs underwent an IV isotope infusion in the fasting state, with a 3-hour NaH 13CO 3 infusion to assess CO 2 production, and immediately thereafter, a 3-hour 13C-leucine infusion to assess leucine appearance rate (Ra), oxidation (Ox), and nonoxidative leucine disposal (NOLD), expressed as μmol.kg −1.h −1. Protein restriction was associated with a 24% decline in leucine Ra (223 ± 16 v 298 ± 17; P < .01), an index of whole body proteolysis, and a 29% decline in NOLD (180 ± 15 v 223 ± 13; P < .01), an index of whole body protein synthesis. In the protein-restricted group, dexamethasone treatment was associated with a 32% increase in Ra, (295 ± 28 v 223 ± 16; P < .05), a 186% increase in Ox (120 ± 14 v 43 ± 4; P < .001), with no change in NOLD, when compared with the protein-restricted alone. After protein restriction + dexamethasone, glutamine infusion induced a 40% increase in plasma glutamine (1,090 ± 70 v 780 ± 29 μmol.L −1; P < .01), but failed to alter Ra, Ox, or NOLD. These results suggest that (1) in dogs, protein restriction combined with a 7-day course of dexamethasone results in alterations in leucine kinetics similar to those observed in stress-induced protein wasting in humans, and (2) in that model, a 7-hour IV glutamine infusion in the fasting state does not significantly attenuate protein wasting.
ISSN:0026-0495
1532-8600
DOI:10.1053/meta.2001.21018