AJP - Endocrinology and Metabolism, Vol 243, Issue 6 505-E511, Copyright © 1982 by American Physiological Society
Altered insulin and glucagon secretion in perfused ethionine-treated rat pancreases
K. V. Axen and F. X. Pi-Sunyer
The endocrine secretory function of rat pancreases in which pancreatitis
had been induced by feeding rats a 0.5% ethionine diet was investigated.
Despite loss of 50% of exocrine tissue and widespread destruction of acinar
structure, pancreatic insulin and glucagon contents and 4-h fasting plasma
insulin levels in vivo did not differ significantly from those of
food-restricted, weight-matched controls. Plasma glucose concentrations
(fasting and after oral glucose) were significantly lower than control. In
isolated, perfused ethionine-treated pancreases secretin failed to
stimulate insulin secretion, whereas basal insulin secretion and insulin
responses to glucose, arginine, gastric inhibitory polypeptide, vasoactive
intestinal peptide (VIP), and somatostatin were similar to those of
controls. Basal glucagon secretion was elevated in ethionine-treated
pancreases, and glucagon outputs in response to arginine, VIP, and
somatostatin showed a consistent trend toward higher levels than those of
controls. These findings demonstrate that ethionine-induced pancreatitis
selectively impairs islet secretory function. These effects may be due to
damage to islet cell membranes by exocrine enzymes and/or a direct
pathogenic action of ethionine on the islets.
