Nonparallelism of digestive enzymes in rat pancreatic hypersecretion.

During a 4 days' cannulation of the pancreatic duct in conscious rats, pancreatic hypersecretion developed. The enzymic composition of the juice altered with time. Amylase secretion reached a plateau after 24 h, whereas the lipase secretion continued to increase for 48 h. The mean trypsinogen and chymotrypsinogen output was three times greater on the 4th day than during the first 24 h. The intrapancreatic content of the enzymes diminished with a different disappearance rate for each enzyme. After 96 h the pancreas contained only 15% of the initial amounts of amylase; lipase also decreased to 15%, chymotrypsinogen to 32% and trypsinogen to 42% of the basal value. Comparison of the rates of synthesis of enzymes on the 1st and the 4th days of study showed an increase of 89% for amylase, 291% for trypsinogen, 300% for chymotrypsinogen and 759% for lipase. It is concluded that the nonparallel content and secretion of digestive enzymes during the course of several days pancreatic hypersecretion is due to different synthesis rates for each enzyme.