title: Glutamine appearance rate in plasma is not increased after gastrointestinal surgery in humans.
abstract: The metabolic response to surgical stress is characterized by muscle protein breakdown and mobilization of amino acids and has been postulated to furnish glutamine and other amino acids to the immune system, gut and liver. The present study was undertaken to investigate whether the whole body appearance rate (R(a))(3) of glutamine in plasma is increased after major elective surgery. Fourteen patients (8 males, 6 females) were measured prior to laparotomy and on the second postoperative day. Patients received a primed continuous 6-h infusion of L-[5-(15) N]glutamine and L-[1-(13)C]leucine, and arterial blood samples and muscle biopsies were taken for concentration and enrichment measurements. As expected, the metabolic response to surgery was characterized by a rise in whole body protein breakdown (n = 14, P < 0.001) and a decreased concentration of glutamine in plasma (n = 14, P < 0.001) and muscle (n = 8, P < 0.01). However, these catabolic changes were not reflected by an increase in the plasma R(a) of glutamine: 246 +/- 8 micromol. kg(-1). h(-1) before surgery vs. 241 +/- 10 micromol. kg(-1). h(-1) on the second postoperative day. We conclude that the whole body R(a) of glutamine in plasma is not increased 2 d after elective gastrointestinal surgery. Further studies are warranted to establish whether the lack of an increase in plasma glutamine R(a) provides a rationale for glutamine supplementation.
authors.affiliation: Department of Surgery, University Hospital Maastricht, NL-6202 AZ Maastricht, The Netherlands.
authors.forename: B A
authors.initials: BA
authors.lastname: van Acker
authors.forename: K W
authors.initials: KW
authors.lastname: Hulsewé
authors.forename: A J
authors.initials: AJ
authors.lastname: Wagenmakers
authors.forename: P B
authors.initials: PB
authors.lastname: Soeters
authors.forename: M F
authors.initials: MF
authors.lastname: von Meyenfeldt
mesh_terms: D000368:Aged; D013505:Digestive System Surgical Procedures; D017558:Elective Surgical Procedures; D005260:Female; D005973:Glutamine / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D006801:Humans; D007262:Infusions, Intravenous; D007813:Laparotomy; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011506:Proteins / Q000378:metabolism*; D014947:Wounds and Injuries / Q000378:metabolism
chemical_list: D011506:Proteins; D005973:Glutamine