title: The gastroenteroinsular response to glucose ingestion during postexercise recovery.
abstract: This study examined gastrointestinal hormone and peptide responses when glucose was ingested after prolonged exercise. Six endurance-trained male athletes ran on a treadmill for 2 h at 60% VO2 max. Immediately after the run, the athletes consumed 75 g of glucose in 250 ml of water (ExGLU) or flavored water as a placebo control (ExPL). On a separate visit, the athletes rested for 2 h and then consumed glucose (ConGLU). During the first 60 min of recovery from exercise alone (ExPL), plasma vasoactive intestinal peptide (VIP), gastrin, and glucagon-like peptide-1 (GLP-1) all increased significantly, whereas glucose, insulin, and gastric inhibitory polypeptide (GIP) were unchanged from the immediate postexercise value. When glucose was ingested after exercise (ExGLU), glucose, insulin, VIP, gastrin, GLP-1, and GIP were all increased (P < 0.01). However, when glucose was ingested after resting for 2 h (ConGLU), VIP levels were unaffected, although glucose, insulin, gastrin, GLP-1, and GIP levels increased (P < 0.05). The plasma glucose response was greater (P < 0.03) and the plasma insulin response lower (P < 0.004) during ExGLU compared with ConGLU. There was a significantly higher (P < 0.01) VIP response during the initial period of recovery in ExGLU than there was with both ExPL and ConGLU. Plasma VIP showed a modest negative correlation with circulating glucose (r = -0.35, P < 0.03) and insulin (r = -0.37, P < 0.03) during the ExGLU recovery period. In summary, when glucose is ingested after prolonged exercise, there is mild insulin resistance and a corresponding rapid transitory increase in plasma VIP. These data suggest that VIP may play an important glucoregulatory role when glucose is ingested during the immediate postexercise recovery period.
authors.affiliation: Division of of Metabolism and Endocrinology, School of Medicine, The Queen's University of Belfast, N. Ireland.
authors.forename: Aine M
authors.initials: AM
authors.lastname: O'Connor
authors.forename: Suresh
authors.initials: S
authors.lastname: Pola
authors.forename: Blathnaid M
authors.initials: BM
authors.lastname: Ward
authors.forename: Davina
authors.initials: D
authors.lastname: Fillmore
authors.forename: Keith D
authors.initials: KD
authors.lastname: Buchanan
authors.forename: John P
authors.initials: JP
authors.lastname: Kirwan
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D004311:Double-Blind Method; D015444:Exercise; D005755:Gastrins / Q000378:metabolism; D005768:Gastrointestinal Hormones / Q000378:metabolism*; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism; D005947:Glucose; D005972:Glutaminase / Q000378:metabolism; D006728:Hormones / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008297:Male; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D005755:Gastrins; D005768:Gastrointestinal Hormones; D006728:Hormones; D007328:Insulin; D047908:Intracellular Signaling Peptides and Proteins; C421249:TAX1BP3 protein, human; D014660:Vasoactive Intestinal Peptide; D052216:Glucagon-Like Peptide 1; D005972:Glutaminase; D005947:Glucose