Postprandial pancreatic secretion and plasma hormones in dogs with pancreatic fistula.

The responses of exocrine pancreas, plasma secretin, and gastrin to a test meal were studied in six dogs prepared with gastric and duodenal fistulas. The experiment was doubly repeated in each dog. Pancreatic juice was diverted to the exterior by direct cannulation into the major pancreatic duct. Volume, bicarbonate, and protein secretion of pancreatic juice were rapidly increased and then gradually reduced after the ingestion of the meal. Plasma secretin concentration reached a peak at 25 min after the ingestion of the meal and remained higher than the basal level for about 3 h. Plasma gastrin concentration rapidly reached a higher plateau which lasted for 40 min after the load of the test meal. A close correlation was observed between bicarbonate secretion and the increment in plasma secretin concentration and between protein secretion and the increment in plasma gastrin concentration. When pancreatic juice is diverted to the exterior, endogenously released secretin and gastrin appear to play an important role in postprandial pancreatic secretion.