AJP - Gastrointestinal and Liver Physiology, Vol 250, Issue 1 15-G20, Copyright © 1986 by American Physiological Society
Effect of exocrine pancreatic secretagogues on circulating somatostatin in dogs
C. Beglinger, G. Ribes, I. Whitehouse, M. M. Loubatieres-Mariani, U. Grotzinger and K. Gyr
Several secretagogues of exocrine pancreatic secretion have been proposed
to act as regulators of pancreatic D-cell function. To characterize this
relationship, we measured incremental responses of protein, bicarbonate,
and circulating somatostatin to graded doses of intravenous cholecystokinin
(CCK-33), CCK-8, caerulein, bombesin, secretin, and intraduodenally
perfused HCl, sodium oleate, and L-phenylalanine in conscious dogs with
gastric and pancreatic fistulas and compared them with postprandial values
(to a beef meal). Bombesin produced dose-related increases in somatostatin
secretion (maximal, 46% of meal response), but caerulein, CCK-33, and CCK-8
released only small amounts of somatostatin at doses equivalent for
pancreatic protein secretion. Secretin did not stimulate somatostatin
release at any dose studied, whereas intraduodenal HCl at a load submaximal
for pancreatic bicarbonate secretion increased somatostatin levels slightly
(maximal, 16% of meal response). L-Phenylalanine and sodium oleate markedly
increased protein secretion, but only oleate clearly stimulated
somatostatin release (maximal, 11% of meal response). Our results suggest a
greater quantitative importance of the intestinal phase for exocrine
pancreatic stimulation than for somatostatin release.
