Effect of acute and chronic oral administration of ethanol on canine exocrine pancreatic secretion

The action of an intragastric injection of ethanol (1.0-1.5 g/kg), either in the fasting animal or with a solid meal, has been studied in two groups of 4 conscious dogs provided with gastric and duodenal Thomas cannulae: one group of 'alcoholic dogs' (AD) had been given 2 g/kg/day ethanol over a period of 24 months, the second group of 'nonalcoholic dogs' (NA) had been given water as control. In NA, intragastric ethanol inhibited water and bicarbonate secretions, alcohol being given in the fasting animal or with a meal. In AD: (a) the nonstimulated output of water and bicarbonate, and to a lesser extent of protein, was decreased compared to NA, protein concentration being increased; (b) the bicarbonate response to a meal without ethanol was decreased, and (c) the most interesting finding is that in AD, the inhibitory action of intragastric ethanol as observed in NA, disappeared and was even replaced by a stimulation of water, bicarbonate and protein secretions. The disappearance in AD of alcohol-induced mechanisms inhibiting pancreatic secretion had already been found with other experimental protocols and involves muscarinic receptors. Inhibition of water and bicarbonate secretions remains unexplained.