AJP - Gastrointestinal and Liver Physiology, Vol 254, Issue 6 864-G869, Copyright © 1988 by American Physiological Society
Role of glucagon in cholecystokinin-stimulated bile flow in dogs
D. L. Kaminski, Y. G. Deshpande and M. C. Beinfeld
Department of Surgery, St. Louis University School of Medicine, Missouri 63104.
Although many choleretic agents are known, their physiological roles and
interrelationships in increasing bile flow remain largely undetermined.
Exogenous cholecystokinin (CCK), glucagon, and insulin are stimulants of
hepatic bile flow in animals and humans. Of possible importance in the
choleresis produced by CCK is the stimulation by exogenous CCK of glucagon
and insulin release from the pancreas. This research evaluates the role of
glucagon and insulin in the choleresis produced by CCK. Dogs with chronic
biliary and gastric fistulas were used. The synthetic octapeptide of CCK
(CCK-8) administered in increasing doses produced progressive increases in
bile volume, bile bicarbonate secretion, and bile chloride concentration
and output. The choleresis produced by CCK-8 was qualitatively similar to
that produced by intravenous glucagon. CCK-8 administration in increasing
doses produced progressive increases in plasma glucagon. When bile flow
changes during CCK-8 administration were correlated with changes in plasma
glucagon, significant correlation existed. CCK-8 significantly increased
serum insulin concentration only at the highest dose of CCK-8 administered.
Somatostatin is an inhibitor of hormone release. Administration of
somatostatin, along with CCK-8, inhibited the choleresis and the increased
plasma glucagon produced by CCK-8 administration alone. During acute
experiments in anesthetized dogs, the pancreas and stomach were removed to
eliminate endogenous glucagon and insulin release. (ABSTRACT TRUNCATED AT
250 WORDS)
