['Cholecystokinin (CCK) stimulates secretion and evokes a hyperplastic response in the rat pancreas. The aims of this study were to measure the effect of chronic hyperCCKemia induced by pancreatico-biliary diversion (PBD) on pancreatic enzyme concentrations, on amylase secretion by dispersed acinar cells, and on the CCK-stimulated secretion of pancreatic juice in PBD-operated rats.', 'Forty-five Sprague-Dawley male rats had either PBD or sham operation 4 weeks before sacrifice or additional experiments. In the first study, 25 rats (13 PBD and 12 sham-operated rats) were either freely fed or fasted overnight before sacrifice. The pancreas was dissected out, weighed and analyzed. In the second study, the rats (6 PBD and 7 sham-operated rats) were fasted overnight before pancreatic acini were prepared. Secretion of amylase during stimulation of acini with CCK-8S and carbachol was measured. In the third study (5 sham-operated and 4 PBD rats), the rats were fasted overnight before basal and CCK-stimulated secretion was measured in vivo.', 'PBD-operated rats showed a threefold increase in pancreatic wet weight with increased contents of DNA, protein and water. The concentration of pancreatic amylase was 7-12% of that found in control animals. The concentrations of trypsin and lipase were also lowered. Stimulation of dispersed pancreatic acini with CCK-8S or carbachol resulted in secretion of amylase to a similar extent in PBD and sham-operated rats. There was no difference in the secretion of pancreatic juice in response to CCK, but although the output of amylase from PBD-operated rats increased with CCK, it remained at a low level throughout the study period.'] Does pancreatic growth after pancreatico-biliary diversion increase the capacity to secrete amylase?