title: Total parenteral nutrition enriched with arginine and glutamate generates glutamine and limits protein catabolism in surgical patients hospitalized in intensive care units.
abstract: OBJECTIVE
  To study the effect of a parenteral nutrition solution enriched with potential precursors of glutamine, i.e., arginine and glutamate, on plasma glutamine concentrations and protein metabolism.
  
  
  METHODS
  Prospective, randomized, single-blind, comparative study.
  
  
  METHODS
  Two intensive care units in two different hospitals.
  
  
  METHODS
  Fifteen surgical patients.
  
  
  METHODS
  Patients were randomized to receive total parenteral nutrition for 5 days with the enriched glutamine precursor solution (GlnP+ group) or a conventional solution (control group), both total parenteral nutrition providing 0.25 gN/kg per day and 35 kcal/kg per day (glucose/lipids, 70%:30%).
  
  
  RESULTS
  Plasma amino acid concentrations before (T0) and after 3 hrs (T3) of perfusion, nitrogen balance (daily and cumulated), and urinary excretion of 3-methylhistidine were measured daily from day 1 to day 5. The two groups were identical for age, weight, severity score, and nitrogen and energy intakes. After a 3-hr perfusion, plasma concentrations of arginine, ornithine, and glutamine increased, and the differences (T3 - T0) were significantly higher in the GlnP+ group: arginine, 107.6+/-7.0 vs. 51.9+/-3.3 (mean over 5 days; p < .001); ornithine, 78.9+/-7.1 vs. 43.6+/-3.1 (p < .001); and glutamine, 32.4+/-8.6 vs. 6.7+/-5.0 micromol/L (p < .05), respectively. A positive correlation was found between arginine and glutamine plasma increases only in the GlnP+ group: r = .45; p < .01 (Spearman's rank-correlation test). Daily and cumulated nitrogen balances were not significantly different between the two groups but were positive (difference from 0) only in the GlnP+ group. The urinary 3-methylhistidine/creatinine ratio decreased significantly from day 1 to day 5 only in the GlnP+ group: 24.5+/-2.7 vs. 18.8+/-2.7 micromol/mmol (p < .05).
  
  
  CONCLUSIONS
  Total parenteral nutrition enriched with arginine and glutamate promotes a better nitrogen balance, limits protein myofibrillar catabolism, and generates glutamine, with arginine (not glutamate) probably being the main contributor to the glutamine-generating effect of the solution through the formation of ornithine.
authors: Laboratoire de Biochimie A, Hôtel-Dieu, AP-HP, Université Paris V, France. luc.cynober@htd.ap-hop-paris.fr
authors: M P
authors: MP
authors: Bérard
authors: J F
authors: JF
authors: Zazzo
authors: P
authors: P
authors: Condat
authors: M P
authors: MP
authors: Vasson
authors: L
authors: L
authors: Cynober
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001120:Arginine / Q000008:administration & dosage* / Q000378:metabolism; D003422:Critical Care; D005260:Female; D018698:Glutamic Acid / Q000008:administration & dosage* / Q000378:metabolism; D006801:Humans; D008297:Male; D008762:Methylhistidines / Q000378:metabolism; D008875:Middle Aged; D009124:Muscle Proteins / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D010289:Parenteral Nutrition, Total; D011183:Postoperative Complications / Q000503:physiopathology / Q000628:therapy*; D011446:Prospective Studies; D016037:Single-Blind Method
chemical_list: D008762:Methylhistidines; D009124:Muscle Proteins; D018698:Glutamic Acid; D001120:Arginine; C028118:3-methylhistidine; D009584:Nitrogen