Abolishment of oral trypsin inhibitor stimulation of the rat exocrine pancreas after duodeno-jejunal resection

Abstract

The effect of long-term oral trypsin inhibitor administration on the exocrine pancreas was studied in unoperated rats and in rats operated on by a 30% proximal small intestinal resection. The following observations were made: in unoperated rats sacrificed 18 hours after the last trypsin inhibitor ingestion there was an increase of the wet weight of pancreas, increase of the pancreatic protein, and an increase of pancreatic and intestinal trypsin(ogen) and of pancreatic amylase by comparison with the controls. In operated rats, treated and examined in an identical way, no influences on the exocrine pancreas were found. It is suggested that the abolishment of the trypsin inhibitor effects on the exocrine pancreas in operated rats reflects the removal of the site of production of one or more intestinal hormone(s) or factor(s) responsible for these effects. In unoperated rats examined 4 hours after the last trypsin inhibitor ingestion a reduction of the pancreatic trypsinogen and amylase and an increase of the intestinal amylase were found, indicating a secretory response of the pancreas to the intraluminal trypsin inhibitor; the low values of intestinal trypsin found in these rats probably reflect inhibition of rat trypsin by the bovine lung trypsin inhibitor.