Studies on the reversibility of oral trypsin inhibitor induced changes of rat pancreatic exocrine enzyme activity and insulin secretory capacity.

Rats were given a daily dose of bovine trypsin inhibitor for 3 weeks (Group 3 A) or 8 weeks (Group 8 A) via an orogastric tube. In another rat group the trypsin inhibitor after 3 weeks was replaced by water for another 5 weeks (Group 8 B). In group 3 A and 8 A an enlargement of the pancreatic gland was found. In group 3 A and 8A the pancreatic protein was increased. In group 3 A and 8 A the pancreatic trypsinogen increased in a more pronounced way than the amylase, while the pancreatic lipase was found to be uninfluenced by the trypsin inhibitor treatment. Five weeks after the cessation of a 3-week treatment the only remaining effect on the exocrine pancreas was an increase of the pancreatic trypsinogen. In group 3A an impairment of insulin secretion following intravenous L-isopropylnoradrenaline and glibenclamide was found. Glucose levels were similar to those of the control rats. Furthermore, a slight decrease of the pancreatic insulin content per g protein was found in these rats. In group 8A and 8B, the insulin secretory pattern was found to be normal following intravenous glucose administration, and an increased glucose elimination rate (k-value) compared with the control group suggested a favourable effect of oral trypsin inhibitor treatment on the glucose tolerance,