AJP - Gastrointestinal and Liver Physiology, Vol 253, Issue 2 139-G145, Copyright © 1987 by American Physiological Society
Endocrine pancreatic morphology and function in exocrine insufficiency in rats
B. Goke, K. Elsebach, W. Hausmann, M. Schaar, R. Arnold and G. Adler
Exocrine pancreatic insufficiency was induced in rats by injection of oleic
acid into the pancreatic duct. Six weeks after a single injection of 50
microliters oleic acid, the exocrine tissue was reduced by 98%. The islets
of Langerhans remained intact and showed no changes in the relative
distribution of beta-, alpha-, D-, and PP-cells. In rats fed ad libitum,
plasma insulin levels and pancreatic insulin content did not differ between
oleic acid-treated animals and controls. The dynamic insulin response was
evaluated in the isolated perfused pancreas. The biphasic pattern of
insulin release after stimulation by glucose was preserved. The
half-maximal (10 mM) glucose-induced insulin release was reduced to 49%
after onset of exocrine atrophy. After stimulation of insulin secretion by
a maximal glucose load (20 mM), the insulin output from the perfused
pancreas was reduced to 56%. A reduction in insulin release to 24% occurred
with respect to the arginine (15 + 10 mM glucose)-stimulated secretion. To
evaluate the significance of these findings in intact animals, glucose
tolerance tests were performed. There were no differences between oleic
acid-, saline-, or untreated animals with respect to serum glucose or
plasma insulin levels during the oral glucose tolerance test. The insulin
response after intravenous glucose in oleic acid-treated rats was not
statistically different from controls. Nevertheless, the serum glucose
levels in rats with exocrine atrophy were above controls, indicating a
slight impairment of glucose tolerance.
