Significance of peptic digestion in rat pancreatic secretory
response to dietary protein.
Guan, Difu, and Gary M. Green.
Department of Physiology, University of Texas Health Science
Center, San Antonio, TX 78284-7756
APStracts 3:0003G, 1996.
The importance of peptic digestion of dietary protein in pancreatic
enzyme secretion and cholecystokinin (CCK) release was investigated
in conscious rats. Native casein and native bovine serum albumin
(BSA) were infused intragastrically and intraintestinally, and the
effect of peptic predigestion on the pancreatic secretory and plasma
CCK responses to BSA were determined (all infused at 450 mg/h). When
dietary proteins were infused intraduodenally, native casein was a
much stronger stimulant of CCK release (5.8+/-0.6 vs. 1.6+/-0.2 pM)
and pancreatic protein secretion (5592+/-736 vs. 750+/-461, [0
-180]mg.kg-1.min) than native BSA. Infusion by the intragastric route
markedly increased pancreatic protein secretion for BSA, but not for
casein. HCl-pepsin treatment of BSA significantly increased its
ability to increase pancreatic secretion and plasma CCK. Pancreatic
protease binding to native BSA was inferior compared to casein.
Peptic digestion of BSA increased its protease binding activity more
than 3-fold. The results indicate that peptic digestion of dietary
proteins enhances their ability to elicit the pancreatic feedback
stimulatory response.
Received 24 July 1995; accepted in final form 15 December 1995.
APS Manuscript Number G312-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 22 January 96