AJP - Gastrointestinal and Liver Physiology, Vol 250, Issue 4 391-G397, Copyright © 1986 by American Physiological Society
Physiological role and localization of cholecystokinin release in dogs
S. J. Konturek, J. Tasler, J. Bilski, A. J. de Jong, J. B. Jansen and C. B. Lamers
In dogs with pancreatic fistulas, meat feeding and intestinal perfusion
with a sodium oleate or amino acid mixture increased pancreatic protein
secretion to approximately 110, 100, and 50%, respectively, of the response
to cholecystokinin (CCK) at a dose of 85 pmol X kg-1 X h-1. Plasma CCK
response increased in these studies to approximately 100, 180, and 40%,
respectively, of the value obtained with exogenous CCK, suggesting that, in
addition to CCK, other neurohormonal factors contribute to pancreatic
enzyme secretion in response to endogenous stimulants. Feeding and duodenal
oleate or amino acids also stimulate the release of pancreatic polypeptide
(PP), which may be involved in the control of pancreatic secretion in
response to endogenous stimulants, including CCK. Perfusion of the intact
intestine with graded amounts of oleate (0.5-16 mmol/h) produced
dose-dependent increments in plasma CCK and pancreatic protein similar to
those obtained with intravenous infusion of graded doses of CCK (0.85-255
pmol X kg-1 X h-1). Oleate perfusion of isolated Thiry loops (30 cm long)
made of duodenojejunal (D-J) and ileal (I) segments also stimulated protein
secretion but elevated plasma CCK only after perfusion of the D-J but not
of the I loop. We conclude that 1) the endogenous CCK released by various
luminal stimulants drives the pancreatic protein secretion; 2) the release
of CCK is confined to the foregut; and 3) PP concomitantly released by
various intestinal stimulants may contribute to the control of pancreatic
secretion induced by endogenous CCK.
