Simultaneous mechanisms on exocrine pancreatic secretion initiated by alcohol in the conscious dog.

Modifications of pancreatic secretion induced by the infusion of alcohol were investigated in seven Thomas fistula dogs. Acute intravenous injections of low doses of alcohol induced a significant increase of all parameters of pancreatic secretion. On the contrary the acute intravenous injection of high doses of alcohol induced a significant decrease of pancreatic secretion. A prolonged-alcohol intravenous infusion producing a stable blood alcohol level provoked at first a decrease of pancreatic secretion, significant only for protein output, followed by a significant increase of all parameters of pancreatic secretion. A spontaneous return to prealcohol values of pancreatic secretion was observed in all cases even if the blood alcohol level remained high and stable and despite four hours of experimentation. Upon the background of a stable blood alcohol level, pentolinium did not suppress alcohol-induced stimulation of water and bicarbonate outputs but did abolish the postalcohol changes in protein secretion. Furthermore, atropine abolished all postalcohol changes in pancreatic secretion. Consequently, there are two responses (inhibition and stimulation) to alcohol which coexist in normal dogs. They are related to the blood alcohol levels and are transitory. These responses involve the vagus nerves. Alcohol appears to stimulate the exocrine pancreas through receptors at different levels of the nervous system.