Hormonal control of avian pancreas by gastrin-releasing peptide from the proventriculus.
Endocrine cells in the acid-secreting part of the avian stomach, the proventriculus, contain two forms of gastrin-releasing peptide (GRP) of 27 and 6 residues, respectively. We have examined the actions of exogenous GRP-27 and GRP-6 and endogenously released GRP in the control of pancreatic secretion in urethan-anesthetized turkeys. Chicken GRP-27 and the structurally related amphibian peptide bombesin were potent stimulants of fluid and protein output from the pancreas (at 6-100 pmol/kg, iv). GRP-6 had no significant effect at doses up to 1,000 times higher. A bombesin antagonist, (CH3)2-CHCO-[D-Ala24]GRP-20--26-NHCH3, inhibited the action of exogenous chicken GRP-27 but did not inhibit intravenous cholecystokinin octapeptide (CCK-8). Distension of the proventriculus with a solution of peptone produced an increase in the flow of pancreatic juice and an increase in protein output, which was not reduced by atropine. The bombesin antagonist produced a reversible inhibition of this response. A CCK-gastrin antagonist, BOC-beta-Ala-Trp-Leu-Asp-O(CH2)2- phenyl(4F), which inhibited the action of exogenous CCK, had no effect on the pancreatic response to exogenous GRP-27 or to distension of the proventriculus with peptone. We suggest that protein-rich solutions in the proventriculus release GRP, which in turn acts directly on the pancreas to stimulate enzyme secretion.
Campbell
B
B
Physiological Laboratory, University of Liverpool, United Kingdom.
Garner
A
A
Dimaline
R
R
Dockray
G J
GJ
D000595:Amino Acid Sequence; D000704:Analysis of Variance; D000818:Animals; D001570:Benzodiazepinones / Q000494:pharmacology; D001839:Bombesin / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology; D002766:Cholecystokinin / Q000037:antagonists & inhibitors; D020109:Devazepide; D019886:Gastrin-Releasing Peptide; D005768:Gastrointestinal Hormones / Q000502:physiology*; D008297:Male; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000494:pharmacology; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*; D010455:Peptides / Q000037:antagonists & inhibitors / Q000502:physiology*; D010461:Peptones / Q000502:physiology; D011531:Proventriculus / Q000502:physiology*; D014422:Turkeys
D001570:Benzodiazepinones; D005768:Gastrointestinal Hormones; D009842:Oligopeptides; D010455:Peptides; D010461:Peptones; C061858:ICI 216140; D019886:Gastrin-Releasing Peptide; D002766:Cholecystokinin; D020109:Devazepide; D001839:Bombesin