Chymotrypsin Inhibitor Stimulation of Pancreatic Enzyme Secretion in the Rat (35332)

Experiments were conducted to investigate the effect of dietary chymotrypsin inhibitor on pancreatic enzyme secretion in the rat, and to compare the response to that evoked by soy bean trypsin inhibitor. Potato chymotrypsin inhibitor evoked a moderately exaggerated pancreatic response compared to casein-fed controls, as demonstrated by a depletion of pancreatic trypsin, chymotrypsin, and lipase activities, and a concomitant increase in the activities of intestinal trypsin and lipase. The PCI-induced response was not nearly as pronounced as that produced by SBTI, in addition to being somewhat delayed. Intestinal trypsin activity in SBTI-fed rats, and chymotrypsin activity in PCI-fed rats, were much less than in controls—often lower than in the fasting state—reflecting an almost total inhibition of the enzymes by their inhibitors as they passed through the gut. In rats fed SBTI, the large increase in intestinal proteolytic enzyme activity was due almost exclusively to chymotrypsin.