title: Endogenously released GLP-1 is not sufficient to alter postprandial glucose regulation in the dog.
abstract: Glucagon-like peptide-1 (GLP-1) is secreted from the L cell of the gut in response to oral nutrient delivery. To determine if endogenously released GLP-1 contributes to the incretin effect and postprandial glucose regulation, conscious dogs (n = 8) underwent an acclimation period (t = -60 to -20 min), followed by a basal sampling period (t = -20 to 0 min) and an experimental period (t = 0-320 min). At the beginning of the experimental period, t = 0 min, a peripheral infusion of either saline or GLP-1 receptor (GLP-1R) antagonist, exendin (9-39) (Ex-9, 500 pmol/kg/min), was started. At t = 30 min, animals consumed a liquid mixed meal, spiked with acetaminophen. All animals were studied twice (± Ex-9) in random fashion, and the experiments were separated by a 1-2-week washout period. Antagonism of the GLP-1R did not have an effect, as indicated by repeated-measures MANOVA analysis of the Δ AUC from t = 45-320 min of arterial plasma glucose, GLP-1, insulin, glucagon, and acetaminophen levels. Therefore, endogenous GLP-1 is not sufficient to alter postprandial glucose regulation in the dog.
authors.affiliation: Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA. johnsonkms@beloit.edu
authors.forename: Kathryn M S
authors.initials: KM
authors.lastname: Johnson
authors.forename: Tiffany
authors.initials: T
authors.lastname: Farmer
authors.forename: Kathleen
authors.initials: K
authors.lastname: Schurr
authors.forename: E
authors.initials: E
authors.lastname: Patrick Donahue
authors.forename: Ben
authors.initials: B
authors.lastname: Farmer
authors.forename: Doss
authors.initials: D
authors.lastname: Neal
authors.forename: Alan D
authors.initials: AD
authors.lastname: Cherrington
mesh_terms: D000082:Acetaminophen; D000818:Animals; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism*; D004285:Dogs / Q000502:physiology*; D019858:Enteroendocrine Cells / Q000378:metabolism; D005260:Female; D005502:Food; D005746:Gastric Emptying; D005934:Glucagon / Q000097:blood; D052216:Glucagon-Like Peptide 1 / Q000097:blood / Q000378:metabolism / Q000502:physiology*; D000067757:Glucagon-Like Peptide-1 Receptor; D006706:Homeostasis / Q000502:physiology; D007328:Insulin / Q000097:blood; D007700:Kinetics; D008297:Male; D010446:Peptide Fragments; D018027:Receptors, Glucagon / Q000037:antagonists & inhibitors
chemical_list: D001786:Blood Glucose; D000067757:Glucagon-Like Peptide-1 Receptor; D007328:Insulin; D010446:Peptide Fragments; D018027:Receptors, Glucagon; D000082:Acetaminophen; C083773:exendin (9-39); D052216:Glucagon-Like Peptide 1; D005934:Glucagon