Peptide YY inhibits the insulinotropic action of gastric inhibitory polypeptide.
Peptide YY (PYY) is released from the gut after ingestion of fat or after a meal. The purpose of this investigation was to examine the effect of PYY on gastric inhibitory polypeptide (GIP)-stimulated insulin release in conscious dogs with gastric and duodenal fistulas. In control experiments, 6 dogs received GIP (400 pmol/kg, i.v., for 1 h) and glucose (0.6 g/kg, i.v., for 1 h); the integrated insulin response over a 1-h period was 142 +/- 32.7 ng-60 min/ml. The plasma GIP levels achieved by this procedure were similar to those observed by intraduodenal infusion of Lipomul (2 ml/min), suggesting that the dose of GIP used was within the physiologic range. Intravenous infusion of three different doses of PYY (100, 200, or 400 pmol/kg.h) caused a significant inhibition of insulin release stimulated by GIP + glucose; the integrated insulin response was reduced to 105, 88, and 79 ng-60 min/ml, respectively. On the other hand, PYY (400 pmol/kg.h) had no effect on insulin secretion induced by intravenous glucose (0.6 g/kg.h) alone. These results indicate that PYY specifically inhibits the insulinotropic action of GIP and that PYY may play a negative-feedback regulatory role in the enteroinsular axis.
Guo
Y S
YS
Department of Surgery, University of Texas Medical Branch, Galveston.
Singh
P
P
Draviam
E
E
Greeley
G H
GH
Thompson
J C
JC
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004285:Dogs; D004378:Duodenal Diseases / Q000378:metabolism; D005260:Female; D005747:Gastric Fistula / Q000378:metabolism; D005749:Gastric Inhibitory Polypeptide / Q000378:metabolism*; D005768:Gastrointestinal Hormones / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism*; D007412:Intestinal Fistula / Q000378:metabolism; D008297:Male; D019894:Peptide YY; D010455:Peptides / Q000494:pharmacology*; D013268:Stimulation, Chemical
D001786:Blood Glucose; D005768:Gastrointestinal Hormones; D007328:Insulin; D010455:Peptides; D019894:Peptide YY; D005749:Gastric Inhibitory Polypeptide