AJP - Gastrointestinal and Liver Physiology, Vol 251, Issue 4 553-G558, Copyright © 1986 by American Physiological Society
Endogenous cholecystokinin drives gallbladder emptying in dogs
K. Shiratori, S. Watanabe, W. Y. Chey, K. Y. Lee and T. M. Chang
We investigated the effect of fat in the duodenum on the gallbladder
emptying in seven dogs prepared with gastric, duodenal, and gallbladder
cannulas. Gallbladder volume was measured at 15-min intervals, and venous
blood samples were obtained at regular intervals for 2.5 h. Intraduodenal
administration of Lipomul (pH 5.0, corn oil) in three different doses (1.1,
2.2, and 4.4 mmol/10 min) resulted in significant increases in gallbladder
emptying in a dose-dependent manner (r = 0.8668, P less than 0.001).
Likewise, the increase in integrated cholecystokinin (CCK) release in
response to Lipomul was also dose dependent (r = 0.7334, P less than
0.001). A statistically significant correlation was found between
integrated CCK release and gallbladder emptying in response to Lipomul (P
less than 0.001). To determine the role of circulating endogenous CCK on
gallbladder emptying effects of intravenous administration of proglumide
and a rabbit anti-CCK serum on gallbladder emptying were studied.
Gallbladder emptying was virtually abolished by the antiserum. Proglumide
not only abolished the emptying but also increased gallbladder volume. Thus
we conclude that in dogs the gallbladder emptying in response to fat in the
upper small intestine depends on increased circulating endogenous CCK.
