The influence of the colon on postprandial glucagon-like peptide 1 (7-36) amide concentration in man.
Glucagon-like peptide (7-36) amide (GLP-1) is an incretin hormone of the enteroinsular axis released rapidly after meals despite the fact that GLP-1 secreting cells (L-cells) occur predominantly in the distal gut. The importance of these colonic L-cells for postprandial GLP-1 was determined in healthy control subjects and in ileostomy patients with minimal small bowel resection (<5 cm). Subjects were fed a high complex carbohydrate test meal (15.3 g starch) followed by two carbohydrate-free, high fat test meals (25 g and 48.7 g fat respectively). Circulating levels of glucose, insulin, glucagon, glucose insulinotrophic peptide (GIP) and GLP-1 were measured over a 9-h postprandial period. For both subject groups the complex carbohydrate test meal failed to elicit a rise in either GIP or GLP-1. However, both hormones were elevated after the fat load although the GLP-1 concentration was significantly reduced in the ileostomist group when compared with controls (P=0.02). Associated with this reduction in circulating GLP-1 was an elevation in glucagon concentration (P=0.012) and a secondary rise in the plasma glucose concentration (P=0.006). These results suggest that the loss of colonic endocrine tissue is an important determinant in the postprandial GLP-1 concentration. Ileostomists should not be assumed to have normal enteroinsular function as the colon appears to have an important role in postprandial metabolism.
Robertson
M D
MD
Human Nutrition Research Centre, Department of Biological and Nutritional Sciences, University of Newcastle, Newcastle-upon-Tyne NE1 7RU, UK.
Livesey
G
G
Morgan
L M
LM
Hampton
S M
SM
Mathers
J C
JC
D000704:Analysis of Variance; D001786:Blood Glucose / Q000032:analysis; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000601:surgery; D003106:Colon / Q000378:metabolism*; D005934:Glucagon / Q000097:blood; D052216:Glucagon-Like Peptide 1; D004763:Glucagon-Like Peptides; D006801:Humans; D007081:Ileostomy; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D018377:Neurotransmitter Agents / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D019518:Postprandial Period
D001786:Blood Glucose; D007328:Insulin; D018377:Neurotransmitter Agents; D010446:Peptide Fragments; C055453:glucagon-like peptide 1 (7-36)amide; D004763:Glucagon-Like Peptides; D052216:Glucagon-Like Peptide 1; D005934:Glucagon