Does feedback regulation of pancreatic enzyme secretion by duodenal trypsin exist in cholecystectomized patients?

Recent studies have supported the existence of a feedback regulation of pancreatic enzyme secretion in man. The aim of present study was to evaluate whether a feedback regulation of pancreatic enzyme secretion exists in cholecystectomized patients. The study was carried out in 12 healthy volunteers and in 6 cholecystectomized patients, 7-14 years (mean 9 years) after the operation. Pancreatic secretion was stimulated by intraduodenal infusion of L-phenylalanine (100 mmo 1.1-1). The calculated outputs of pancreatic alpha-amylase and lipase were estimated. The feedback phenomenon was studied using consecutive intraduodenal infusion of trypsin (300 mg/h) and aprotinin (1.5 x 10(6) KIU/30 min). In 6 healthy persons, the infusion of trypsin caused a significant decrease (35-45%) in phenylalaninestimulated alpha-amylase and lipase outputs (p less than 0.05). This effect was completely reversed by intraduodenal aprotinin infusion. In contrast, the increase or the inhibition of tryptic activity in the duodenum was without any effect on pancreatic secretion in cholecystectomized patients. A feedback control of pancreatic secretion could not be demonstrated in patients 6-14 years after cholecystectomy.