Cholecystokinin secretion in patients with chronic pancreatitis and after different types of pancreatic surgery

Cholecystokinin (CCK) secretion may be affected in patients with chronic pa ncreatitis (CP), but little is known on the effect of pancreatic surgery on CCK secretion. We measured CCK secretion (radioimmunoassay, RIA) in respon se to bombesin infusion (100 ng/kg/20 min) for 120 min to test CCK secretor y capacity, to ingestion of a liquid diet (400 kcal) for 120 min, and in re sponse to a solid fat-rich meal (500 kcal) for 120 min. These studies were performed in 45 patients with CP (25 with exocrine insufficiency), 15 patie nts after duodenum-preserving pancreatic head resection (DPRHP), 18 patient s after the Whipple operation, 12 patients after distal pancreatectomy (DP) , and 35 control subjects. In CP patients, the CCK secretory capacity was p reserved, but the postprandial CCK response was reduced, depending on meal composition and the presence of exocrine insufficiency. In patients after W hipple's operation, CCK secretory capacity and postprandial CCK secretion w ere significantly (p < 0.05) reduced. In patients after DPRHP, CCK secretor y capacity was not affected, but the postprandial CCK response was signific antly (p < 0.05) reduced, depending on meal composition and the presence of exocrine insufficiency. In patients after DPRHP, fasting plasma CCK levels were significantly (p < 0.01) increased, pointing to the absence of feedba ck inhibition on CCK secretion by intraluminal enzymes. After DP, the CCK s ecretory capacity was not affected. In conclusion: alterations in CCK secre tion are observed in patients with chronic pancreatitis and after pancreati c surgery. These alterations are related not only to the disease process (e xocrine insufficiency) but also to the type of surgery and type of stimulus .