Rapid adaptation of pancreatic enzyme secretion in the conscious rat. II. Effects of fasting and dietary modulation.

The influence of fasting and dietary modulation on basal and stimulated pancreatic enzyme secretion was studied in conscious rats with cannulated pancreatic ducts. Two days' fasting decreased pancreatic secretion by about 30%. After stimulation of the secretion rate by acute derivation of pancreatic juice or by intravenous infusion of cerulein (0.2 micrograms/kg/h) no rapid change of enzyme composition was found. In further experiments, two groups of rats were fed with carbohydrate-rich and carbohydrate-poor diets, respectively. After pancreatic duct cannulation and a postsurgical recovery period, the diets were interchanged. An adaptation of pancreatic enzyme secretion to the new diet was observed in pancreatic juice. Stimulation of the secretion rate during the adaptation process by acute derivation of the juice or by intravenous infusion of either cerulein, secretin, carbachol or cerulein plus secretin did not further modify the composition of pancreatic proteins. 'Nonparallel' secretion of enzymes was never found when sufficient time for recovery from pancreatic duct surgery was allowed.