Canine exocrine pancreatic secretory changes induced by an intragastric ethanol test meal

In five dogs with chronic gastric fistulas (Thomas cannula) and a new type of chronic pancreatic fistula which permits collection of pure nonactivated pancreatic juice after ingestion of a test meal, the following series of experiments were performed: In the first series, a test meal (400 gm. canned dog meat) was given with 200 ml. saline simultaneously infused through the gastric cannula. In response to this stimulus, the 20-minute peak pancreatic flow rate and bicarbonate output were respectively 33% and 34%, of the maximal secretion of the pancreatic gland obtained with secretin in six control dogs provided with gastric and the classical Thomas duodenal fistula. The 20-minute peak protein output represented 84% of the maximal secretory capacity attained with dose-response curves to CCK in the same group of control animals. In the second series either 1.5 or 2.0 gm./kg. ethanol were given instead of saline. Intragastric ethanol induced a dissociation of pancreatic secretion: a significant inhibition of flow rate, of bicarbonate concentration and output and a significant rise of protein concentration; protein output remaining unchanged. It is postulated that ethanol, acting on the stomach and duodenojejunum, evokes, independently of its gastrin-releasing capacity, and unknown humoral or nervous mechanism that counteracts the ethanol-elicited cholinergic-mediated inhibition of pancreatic protein secretion which has been previously described.