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

Cholecystokinin (CCK) secretion may be affected in patients with chronic pancreatitis (CP), but little is known on the effect of pancreatic surgery on CCK secretion. We measured CCK secretion (radioimmunoassay, RIA) in response to bombesin infusion (100 ng/kg/20 min) for 120 min to test CCK secretory capacity, to ingestion of a liquid diet (400 kcal) for 120 min, and in response 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 patients after duodenum-preserving pancreatic head resection (DPRHP), 18 patients after the Whipple operation, 12 patients after distal pancreatectomy (DP), and 35 control subjects. In CP patients, the CCK secretory capacity was preserved, but the postprandial CCK response was reduced, depending on meal composition and the presence of exocrine insufficiency. In patients after Whipple's operation, CCK secretory capacity and postprandial CCK secretion were significantly (p < 0.05) reduced. In patients after DPRHP, CCK secretory capacity was not affected, but the postprandial CCK response was significantly (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 feedback inhibition on CCK secretion by intraluminal enzymes. After DP, the CCK secretory capacity was not affected. In conclusion: alterations in CCK secretion are observed in patients with chronic pancreatitis and after pancreatic surgery. These alterations are related not only to the disease process (exocrine insufficiency) but also to the type of surgery and type of stimulus.