AJP - Gastrointestinal and Liver Physiology, Vol 248, Issue 1 28-G34, Copyright © 1985 by American Physiological Society
Effect of divalent cations on gastrointestinal hormone release and exocrine pancreatic secretion in dogs
K. Inoue, G. M. Fried, I. Wiener, T. Sakamoto, P. Lilja, G. H. Greeley Jr, L. C. Watson and J. C. Thompson
The purpose of this study was to examine the effect of three common
divalent cations (Ca2+, Mg2+, and Zn2+) on the release of cholecystokinin
(CCK-33), pancreatic polypeptide (PP), and gastrin. Five dogs with
pancreatic and gastric fistulas were given 1-h intraduodenal infusions of
calcium (5 mmol X kg-1 X h-1), magnesium (4 mmol X kg-1 X h-1), or zinc (1
mmol X kg-1h-1). At another time the same dogs were given an intravenous
bolus followed immediately by a 1-h infusion of calcium (0.36 mmol/kg
[bolus], 0.36 mmol X kg-1 X h-1), magnesium (0.25 mmol/kg [bolus], 0.25
mmol X kg-1 X h-1), or zinc (0.03 mmol/kg [bolus], 0.03 mmol X kg-1 X h-1).
Intraduodenal infusions of calcium, magnesium, and zinc significantly
stimulated CCK-33, PP, and gastrin release. Intravenous calcium stimulated
CCK-33, PP, and gastrin release to 245, 193, and 155% of basal levels,
respectively. Intravenous magnesium increased CCK-33 to 123% of basal
levels but did not stimulate PP and gastrin levels. Intravenous zinc
stimulated release of CCK-33, PP, and gastrin to 126, 185, and 124%,
respectively. This study shows that calcium, magnesium, and zinc can
stimulate release of CCK-33, PP, and gastrin in much the same manner. We
suggest that these cations may have a nonspecific electrical action that
results in an alteration of membrane permeability, which leads to release
of gastrointestinal hormones.
