title: Effects of exogenous glucagon-like peptide-1 on the blood pressure, heart rate, mesenteric blood flow, and glycemic responses to intraduodenal glucose in healthy older subjects.
abstract: BACKGROUND
  Studies relating to the cardiovascular effects of glucagon-like peptide-1 (GLP-1) and its agonists, which slow gastric emptying, have not discriminated between fasting and postprandial, blood pressure (BP) and heart rate (HR).
  
  
  OBJECTIVE
  To determine whether exogenous GLP-1 modulates the effects of an intraduodenal (ID) glucose infusion on BP, HR, and splanchnic blood flow in healthy older subjects.
  
  
  METHODS
  A double-blind randomized trial was conducted.
  
  
  METHODS
  Community-dwelling residents attended a clinical research laboratory.
  
  
  METHODS
  Ten healthy "older" subjects (9 male, 1 female; age 73.2 ± 1.5 y) were studied.
  
  
  METHODS
  Intravenous infusion of GLP-1 (0.9 pmol/kg/min), or saline (0.9%) for 90 min (t = -30-60 min). Between t = 0-60 min, ID glucose was infused at 3 kcal/min.
  
  
  METHODS
  BP, HR, superior mesenteric artery (SMA) flow, blood glucose, and serum insulin were measured.
  
  
  RESULTS
  During the fasting period (t = -30-0 min), GLP-1 had no effect on BP or HR. In response to ID glucose (t = 0-60 min), systolic BP decreased (P < .001), and both HR (P < .001) and SMA flow (P < .05) increased, on both days. GLP-1 attenuated the maximum decrease in systolic BP (P < .05), tended to increase HR (P = .09), and increased SMA flow (P < .01). GLP-1 diminished the glycemic response (P < .05).
  
  
  CONCLUSIONS
  In healthy older subjects, acute administration of GLP-1 attenuates the hypotensive response to ID glucose, and potentiates the increase in SMA flow.
authors.affiliation: Discipline of Medicine (L.G.T., M.H., C.F.-B., C.K.R., K.L.J.), The University of Adelaide, Adelaide 5005, Australia; National Health and Medical Research Council Centre of Research Excellence in Translating Nutritional Science to Good Health (L.G.T., M.H., C.F.-B., C.K.R., K.L.J.), The University of Adelaide, Adelaide 5005, Australia; and Section for Gastroenterology (T.H.), Department of Clinical Medicine, University of Bergen, N-5020 Bergen, Norway.
authors.forename: Laurence G
authors.initials: LG
authors.lastname: Trahair
authors.forename: Michael
authors.initials: M
authors.lastname: Horowitz
authors.forename: Trygve
authors.initials: T
authors.lastname: Hausken
authors.forename: Christine
authors.initials: C
authors.lastname: Feinle-Bisset
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Rayner
authors.forename: Karen L
authors.initials: KL
authors.lastname: Jones
mesh_terms: D000368:Aged; D001341:Autonomic Nervous System / Q000187:drug effects; D001786:Blood Glucose / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects*; D004311:Double-Blind Method; D004386:Duodenum / Q000378:metabolism*; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000494:pharmacology*; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007328:Insulin / Q000097:blood; D007441:Intubation, Gastrointestinal; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects; D013152:Splanchnic Circulation / Q000187:drug effects*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D052216:Glucagon-Like Peptide 1; D005947:Glucose