Influence of chronic ethanol consumption on the muscarinic cholinergic control of rat pancreatic acinar cells

There are a number of hypothetical explanations for the actions of ethanol on the exocrine pancreas; among them, the cholinergic hypothesis has receiv ed special attention. According to this hypothesis, chronic alcohol consump tion induces alterations in the control of exocrine pancreatic function res ulting in cholinergic hyperstimulation of pancreatic acinar cells and their muscarinic receptors. Our aim was to investigate the cholinergic control o f pancreatic enzyme secretion and the number and affinity of muscarinic rec eptors in the pancreatic acinar cells of rats subjected to chronic ethanol ingestion. We also investigated whether a high-fibre diet modifies the acti ons of ethanol on these aspects of the exocrine pancreatic function. Four g roups of rats received either a standard or a high fibre diet, and either w ater or 20 % (v/v) ethanol. After 6 months of treatment, isolated pancreati c acini were used for the determination of carbachol-stimulated amylase sec retion and for the analysis of muscarinic receptors, using 1-[N-methyl-H-3] scopolamine as a radioligand. Neither chronic ethanol intake nor a high fib re diet caused any apparent, alteration in pancreatic histology, neither di d them modify plasmatic amylase levels. Chronic alcoholization resulted in a significant increase in the amylase released from pancreatic acini in res ponse to carbachol stimulation, but it did not affect either the number or the affinity of pancreatic acinar muscarinic receptors. The actions of etha nol are not significantly modified by the simultaneous consumption of a hig h fibre diet.