THE EFFECT OF GLUTAMINE-ENRICHED AND ALANINE-ENRICHED TOTAL PARENTERAL-NUTRITION ON POSTBURN PROTEOLYSIS IN THE RAT

This study compared the effects of total parenteral nutrition (TPN) su pplemented with either glutamine (GLN) or alanine (ALA) on postburn pr oteolysis in the mt. Thirty adult Sprague-Dawley rats underwent cathet erization of the superior vena cava and placement of a swivel apparatu s. One group (CONTROL, N = 18) was then returned to their cages while the remaining animals (BURN, N = 12) received a full-thickness scald b urn (approximately 20% BSA). CONTROL and BURN rats were then randomly assigned to receive TPN supplemented with either GLN or ALA. TPN consi sted of dextrose (250 Kcal/Kg BW/day) and crystalline amino acids (0.9 gN/kg BW/day) composed of all essential amino acids, histidine, argin ine, glycine, and either ALA or GLN (1.2 g/100 mg). TPN was administer ed for 3 days after the burn. Urinary 3-methyl histidine (3MH) and nit rogen excretions were determined, and blood amino acids were measured. Both BURN groups had significantly higher 3MH excretion and blood lev els of branched chain amino acids (BCAA) and alanine than both CONTROL groups. In both BURN and CONTROL groups, GLN-TPN did not significantl y affect 3MH excretion or the blood levels of BCAA or alanine compared with ALA-TPN. In BURN animals, GLN-TPN resulted in significantly high er urinary nitrogen excretion than ALA-TPN resulting in lower nitrogen retention. Compared with ALA-TPN, GLN-TPN produced greater urinary ni trogen losses and did not reduce protein catabolism. (C) Elsevier Scie nce Inc. 1998.