AJP - Gastrointestinal and Liver Physiology, Vol 238, Issue 2 119-G123, Copyright © 1980 by American Physiological Society
Effect of glucagon on bile cAMP secretion
D. L. Kaminski, W. H. Brown and Y. G. Deshpande
The effect of bile flow and adenosine 3',5'-cyclic monophosphate (cAMP)
secretion of substances that alter cAMP metabolism in other systems was
evaluated. The experiments were performed on awake dogs with chronic
biliary and gastric fistulas and on anesthetized rabbits prepared with
acute bile fistulas. In all experiments the enterohepatic circulation was
maintained by intravenous bile salt administration. In dogs, glucagon
increased bile flow and bile cAMP secretion with 4 micrograms . kg-1 . h-1
increasing bile flow from control values of 273 +/- 27 to 413 +/- 6
microliters/min, whereas bile cAMP concentration rose from 3.9 +/- 0.9 to
12.1 +/- 1.1 nmol/ml. Theophylline in dogs increased bile flow while cAMP
secretion decreased. Evaluation of the effects of theophylline on
glucagon-stimulated bile flow suggest that both agents act by the same
mechanism; however, theophylline did not significantly alter
glucagon-stimulated increases in bile cAMP. In rabbits, glucagon increased
bile cAMP secretion while bile flow was not significantly changed. Hormonal
production of increased systemic or hepatic cAMP can increase bile cAMP
unassociated with changes in bile flow. Based on the measurement of cAMP in
bile the increase in glucagon-stimulated bile flow produced by theophylline
is not cAMP mediated.
