AJP - Gastrointestinal and Liver Physiology, Vol 238, Issue 3 213-G218, Copyright © 1980 by American Physiological Society
Bombesin-induced desensitization of enzyme secretion in dispersed acini from guinea pig pancreas
P. C. Lee, R. T. Jensen and J. D. Gardner
Incubating dispersed acini from guinea pig pancreas with bombesin and then
washing the cells to remove bombesin reduced the subsequent stimulation of
amylase secretion caused by bombesin, litorin, or ranatensin by as much as
80%, but did not alter the stimulation of amylase secretion caused by
cholecystokinin, carbamylcholine, A23187 or vasoactive intestinal peptide.
This bombesin-induced desensitization was reversible, and the onset of the
process, as well as its reversal, were time and temperature dependent.
Neither desensitization or resensitization were inhibited by abolishing
protein synthesis. The concentrations of bombesin required to cause
desensitization were in the same range as those required to stimulate
amylase secretion. Incubating pancreatic acini with vasoactive intestinal
peptide did not reduce the subsequent stimulation of amylase secretion
caused by vasoactive intestinal peptide, bombesin, or cholecystokinin.
These results indicate that bombesin-induced desensitization of pancreatic
acini reflects changes that occur at or close to the bombesin receptor.
