title: Effects of intraduodenal glutamine on incretin hormone and insulin release, the glycemic response to an intraduodenal glucose infusion, and antropyloroduodenal motility in health and type 2 diabetes.
abstract: OBJECTIVE
  Glutamine reduces postprandial glycemia when given before oral glucose. We evaluated whether this is mediated by stimulation of insulin and/or slowing of gastric emptying.
  
  
  METHODS
  Ten healthy subjects were studied during intraduodenal (ID) infusion of glutamine (7.5 or 15 g) or saline over 30 min, followed by glucose (75 g over 100 min), while recording antropyloroduodenal pressures. Ten patients with type 2 diabetes mellitus (T2DM) were also studied with 15 g glutamine or saline.
  
  
  RESULTS
  ID glutamine stimulated glucagon-like peptide 1 (GLP-1; healthy: P < 0.05; T2DM: P < 0.05), glucose-dependent insulinotropic polypeptide (GIP; P = 0.098; P < 0.05), glucagon (P < 0.01; P < 0.001), insulin (P = 0.05; P < 0.01), and phasic pyloric pressures (P < 0.05; P < 0.05), but did not lower blood glucose (P = 0.077; P = 0.5).
  
  
  CONCLUSIONS
  Glutamine does not lower glycemia after ID glucose, despite stimulating GLP-1, GIP, and insulin, probably due to increased glucagon. Its capacity for pyloric stimulation suggests that delayed gastric emptying is a major mechanism for lowering glycemia when glutamine is given before oral glucose.
authors.affiliation: Discipline of Medicine, University of Adelaide, Royal Adelaide Hospital, Adelaide, South Australia, Australia.
authors.forename: Jessica
authors.initials: J
authors.lastname: Chang
authors.forename: Tongzhi
authors.initials: T
authors.lastname: Wu
authors.forename: Jerry R
authors.initials: JR
authors.lastname: Greenfield
authors.forename: Dorit
authors.initials: D
authors.lastname: Samocha-Bonet
authors.forename: Michael
authors.initials: M
authors.lastname: Horowitz
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Rayner
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000187:drug effects*; D003924:Diabetes Mellitus, Type 2; D004386:Duodenum; D005260:Female; D005746:Gastric Emptying / Q000187:drug effects*; D005749:Gastric Inhibitory Polypeptide / Q000097:blood; D005934:Glucagon / Q000097:blood; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D005947:Glucose / Q000494:pharmacology*; D005973:Glutamine / Q000494:pharmacology*; D064368:Healthy Volunteers; D006801:Humans; D054795:Incretins; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male
chemical_list: D001786:Blood Glucose; D054795:Incretins; D007328:Insulin; D005973:Glutamine; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D005947:Glucose
references.citation: Diabetes Care. 2001 Feb;24(2):371-81
references.pmid: 11213895
references.citation: Diabetes Care. 2009 Sep;32(9):1600-2
references.pmid: 19542012
references.citation: Dig Dis Sci. 1994 Dec;39(12 Suppl):7S-13S
references.pmid: 7995220
references.citation: J Nutr. 2011 Jul;141(7):1233-8
references.pmid: 21593352
references.citation: Diabetes Care. 2003 Mar;26(3):881-5
references.pmid: 12610053
references.citation: Neurogastroenterol Motil. 1998 Apr;10(2):139-48
references.pmid: 9614672
references.citation: Clin Nutr. 2009 Dec;28(6):636-41
references.pmid: 19500889
references.citation: Am J Clin Nutr. 2009 Jan;89(1):106-113
references.pmid: 19056578
references.citation: J Nucl Med. 1996 Oct;37(10):1643-8
references.pmid: 8862300