GLP-1 slows solid gastric emptying and inhibits insulin, glucagon, and PYY release in humans.
The aim of the present study was to assess the effect of glucagon-like peptide-1 (GLP-1) on solid gastric emptying and the subsequent release of pancreatic and intestinal hormones. In eight men [age 33.6 +/- 2.5 yr, body mass index 24.1 +/- 0.9 (means +/- SE)], scintigraphic solid gastric emptying during infusion of GLP-1 (0.75 pmol. kg(-1). min(-1)) or saline was studied for 180 min. Concomitantly, plasma concentrations of C- and N-terminal GLP-1, glucose, insulin, C-peptide, glucagon, and peptide YY (PYY) were assessed. Infusion of GLP-1 resulted in a profound inhibition of both the lag phase (GLP-1: 91.5, range 73.3-103.6 min vs. saline: 19. 5, range 10.2-43.4 min) and emptying rate (GLP-1: 0.34, range 0.06-0. 56 %/min vs. saline: 0.84, range 0.54-1.33 %/min; P < 0.01 for both) of solid gastric emptying. Concentrations of both intact and total GLP-1 were elevated to supraphysiological levels. Plasma glucose and glucagon concentrations were below baseline during infusion of GLP-1 in contrast to saline infusion, where concentrations were elevated above baseline (both P < 0.001). The insulin and C-peptide responses were lower during infusion with GLP-1 than with saline (P < 0.004 and P < 0.001, respectively). Plasma PYY concentrations decreased below baseline during GLP-1 infusion in contrast to saline, where concentrations were elevated above baseline (P = 0.04). Infusion of GLP-1 inhibits solid gastric emptying with secondary effects on the release of insulin, C-peptide, and glucagon, resulting in lower plasma glucose concentrations. In addition, the release of PYY into the circulation is inhibited by GLP-1 infusion, suggesting a negative feedback of GLP-1 on the function of the L-cell.
Näslund
E
E
Division of Surgery, Danderyd Hospital, Karolinska Institutet, SE-182 88, Stockholm, Sweden. Erik.Naslund@kir.ds.sll.se
Bogefors
J
J
Skogar
S
S
Grybäck
P
P
Jacobsson
H
H
Holst
J J
JJ
Hellström
P M
PM
D000328:Adult; D005746:Gastric Emptying / Q000187:drug effects* / Q000502:physiology*; D005934:Glucagon / Q000097:blood* / Q000494:pharmacology* / Q000502:physiology; D052216:Glucagon-Like Peptide 1; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology* / Q000502:physiology; D019894:Peptide YY / Q000097:blood*; D011498:Protein Precursors / Q000494:pharmacology* / Q000502:physiology
D007328:Insulin; D010446:Peptide Fragments; D011498:Protein Precursors; D019894:Peptide YY; D052216:Glucagon-Like Peptide 1; D005934:Glucagon