THE EFFECTS OF FEEDING AND SECRETIN ADMINISTRATION ON THE PANCREATICODUODENAL PAPILLA OF CONSCIOUS DOGS

The aim of this study was to define the functional role of the pancrea ticoduodenal papilla (PDP) in the regulation of pancreatic outflow int o the duodenum in response to feeding and secretin administration in c onscious dogs. The canine model we developed allowed for measurement o f the pancreatic ductal pressure and pancreatic outflow simultaneously in a physiological state without interfering with the flow of pancrea tic juice via the intact sphincter of the duodenal papilla. Feeding in creased the pancreatic outflow from 2.8 +/- 0.2 to 13.4 +/- 1.3 ml/15 min with a slight increase in the pancreatic ductal pressure from 8.5 +/- 0.6 to 13.7 +/- 1.4 cmH2O. The administration of secretin increase d the pancreatic outflow from 2.8 +/- 0.2 to 12.7 +/- 1.0 ml/15 min wi thout increasing the pancreatic ductal pressure. The viscosity of the pancreatic juice increased during exposure to food, but decreased foll owing food intake and secretin administration, after which the PDP see med to dilate by about 40% of the fasting value. The results suggest t hat PDP changes its opening to maintain the pancreatic ductal pressure below a certain level, even if pancreatic secretion into the pancreat ic duct increases due to food intake and secretin administration.