Pancreatic secretion obtained by endoscopic cannulation of the main pancreatic duct and secretin release after duodenal acidification in man.

The main pancreatic duct was cannulated in 12 individuals with a teflon catheter by means of a side-viewing duodenscope. Six individuals received a duodenal infusion of 40 ml 100 mmol/l HCl over 5 min, while the other six served as controls for basal pancreatic secretion. Pancreatic juice was collected in 5-min samples, and blood was frequently drawn for radioimmunoassay of immunoreactive secretin (IRS). In the control group, during 20-min cannulation of the main pancreatic duct, no effect was seen on basal secretion of water, bicarbonate, or alpha-amylase--nor did the IRS levels change. After duodenal acidification there was a significant increase in IRS (p less than 0.02), reaching the highest level at 7 min. The mean flow rate, bicarbonate concentration, and bicarbonate output showed a significant increase as compared to the control group (p less than 0.02), the highest levels being reached in the third 5-min period after the start of the duodenal acidification. The alpha-amylase output was also significantly higher after acidification (p less than 0.02) than in the control group, but the mean alpha-amylase concentration decreased after acidification, reaching its nadir in the third 5-min sample (p less than 0.02). The present results demonstrate a basal and HCl-stimulated pancreatic secretion collected by endoscopic cannulation of the main pancreatic duct in man together with plasma IRS levels.