PANCREATIC PROTEIN HYPERSECRETION AND ELEVATED PLASMA CCK - PREREQUISITES FOR INCREASED PANCREATIC GROWTH

This study was undertaken to establish if a correlation exists between chronic elevated pancreatic secretion and growth of the pancreas. Rat s provided with jugular, pancreatic, biliary, duodenal, or ileal cannu las were fed throughout the experiment with a liquid diet continuously infused into the duodenum. Four days after surgery, control rats and those infused with cerulein (CE) 0.45 mug/kg/h had their pancreatic ju ice returned into the duodenum. Two other groups had their pancreatic juice either totally diverted outside (DO) or returned into the ileum (DI). In all groups, bile was returned into the duodenum. Pancreatic j uice was collected every 4 h for 4 days with volume and protein determ ined. After 4 days, rats were killed and their pancreata were evaluate d for weight and contents of DNA, RNA. protein, amylase, and chymotryp sinogen. The average volumes/4 h were significantly increased by 259, 241, and 270% in DO, DI, and CE rats, respectively. Protein output rem ained at control levels in DO rats, whereas increases of 200 and 90% a bove control values were observed in DI and CE rats, respectively, dur ing the last periods of collection. Constant drainage of pancreatic ju ice outside (DO) had no effect on pancreatic growth; on the contrary, its reinfusion into the ileum and constant cerulein infusion were asso ciated with impressive growth of the pancreas, with cerulein being the most potent stimulus. In conclusion these data support the hypothesis that increased protein output is associated with pancreatic growth, a phenomenon mediated by endogenous cholecystokinin.