Influence of adrenalectomy on pancreatic enzyme secretion.
Both adrenalectomy and chemically induced diabetes mellitus cause a marked decrease of pancreatic amylase synthesis in rats. Diabetes is further associated with alterations of cholecystokinin (CCK)-stimulated enzyme secretion. Using isolated pancreatic acini prepared from adrenalectomized male rats, we investigated the effects of adrenalectomy on pancreatic enzyme secretion. CCK8-stimulated amylase secretion showed a typical biphasic dose-response curve in acini from both adrenalectomized and sham-operated animals with similar basal secretions, similar sensitivities to various CCK8 concentrations, but a statistically significant elevation of maximal amylase secretion after adrenalectomy. Receptor-binding studies with 125I-BH-CCK8 revealed an increase of binding to the high-affinity part of the CCK receptor in adrenalectomized rats. While carbachol-stimulated secretion showed no changes in maximal secretion rates, it did show a decrease in sensitivity in adrenalectomized animals with a statistically significant shift to the right of the dose-response curves. Competitive inhibition curves with 3H-N-methylscopolamine and carbachol as the competitive receptor agonist showed no differences in receptor binding between controls and adrenalectomized rats. We propose that complex alterations in hormone/neurotransmitter-stimulated pancreatic enzyme secretion are found in glucocorticoid depletion, explainable via a postreceptor defect in carbachol-stimulated secretion. The functional and binding data with regard to CCK are more difficult to explain.
Mössner
J
J
Medizinische Poliklinik, Universität Würzburg, BRD.
Böhm
S
S
Stieber
S
S
D000311:Adrenal Glands / Q000502:physiology*; D000315:Adrenalectomy; D000681:Amylases / Q000378:metabolism*; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D005938:Glucocorticoids / Q000502:physiology; D008297:Male; D010179:Pancreas / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D011949:Receptors, Cholecystokinin / Q000378:metabolism; D012844:Sincalide / Q000378:metabolism / Q000494:pharmacology
D005938:Glucocorticoids; D011949:Receptors, Cholecystokinin; D002217:Carbachol; D000681:Amylases; D012844:Sincalide