Pancreatic juice enhances fat-stimulated release of enteric hormones in dogs

The presence of pancreatic juice in the intestinal lumen results in the hydrolysis of dietary fat. The hydrolytic products of dietary fat are potent stimulants of pancreatic exocrine secretion and potent inhibitors of gastric acid secretion. In this study, residual pancreatic enzyme activity in the intestinal lumen may account for the observed increase of triglyceride-stimulated pancreatic exocrine secretion and the release of peptides during diversion of pancreatic juice. The presence of pancreatic juice enhanced the pancreatic protein output that was stimulated by the intraduodenal administration of a triglyceride (corn oil, 2 g/kg/h) by 240% (p <.05). The presence of pancreatic juice during the intraduodenal administration of a triglyceride nearly abolished the output of gastric acid as well as the release of gastrin (p <.05) that had been stimulated by the intragastric placement of a 10% peptone meal. Pancreatic juice in the duodenum significantly enhanced the triglyceride-stimulated release of cholecystokinin-33/39, secretin, neurotensin, peptide YY, pancreatic polypeptide, and insulin (p <.05) when compared with the release of these entero-pancreatic hormones during the diversion of pancreatic juice. This study shows that the presence of pancreatic juice in the duodenal lumen enhances the fat-stimulated release of enteric hormones that have a stimulatory action on the enteroacinar and enteroinsular axis as well as an inhibitory action (enterogas-trone-like activity) on the postprandial regulation of gastric function.