Canine exocrine pancreatic secretory changes induced by calcium or ethanol plus calcium intraduodenal infusion

In dogs provided with chronic gastric and pancreatic fistulas (Thomas cannula), an 80-minute intraduodenal CaCl2 (0.6 mM/kg.) infusion against a background of secretin perfusion (GIH, 1.0 CU/kg./hr.) elicits a complex "pancreon" response consisting of both excitatory and inhibitory effects on the protein and alkaline components, respectively, of pancreatic secretion. It is postulated that these pancreatic secretion changes are the result of the interplay of released CCK and calcitonin. The lack of pancreatic secretion modifications when ethanol (0.7 mg./kg.) was added to the intraduodenal CaCl2 infusion suggests that the former counteracts the effects of the latter on the nerves and/or the endocrine cells of the gut. Ca++ concentration and output in pancreatic secretion did not change significantly either with the intraduodenal CaCl2 alone or associated with ethanol. Fasting blood Ca++ levels were not modified either by the secretin perfusion or by the intraduodenal CaCl2 infusion, either given alone or associated with ethanol.