Evidence for an intraluminal mediator in rat pancreatic enzyme secretion: reconstitution of the pancreatic response with dietary protein, trypsin and the monitor peptide.
New evidence has been obtained suggesting that the "monitor" peptide is an essential intraluminal mediator in the stimulation of pancreatic enzyme secretion in response to protein intake in rats. Experiments were performed in vivo using a mixture of 50 mg of ovalbumin, alpha-lactalbumin or casein, 2 micrograms of purified protease-sensitive, cholecystokinin-releasing monitor peptide and 1 mg of porcine trypsin which was infused by cannula into the duodenum of atropine-treated rats. The small intestine had previously been washed with bicarbonate to eliminate proteases and the pancreatic juice was diverted. The amount of trypsin secreted in 2 h was comparable to that of rats in which the pancreatic juice was returned into the duodenum. However, in the presence of a monitor peptide--specific antibody which recognizes the N-terminal region of the peptide, the monitor peptide did not induce any pancreatic response. Therefore, the characteristic pattern of pancreatic enzyme secretion in response to protein intake can be reproduced by infusing only three components--dietary proteins, porcine trypsin and the purified monitor peptide.
Fushiki
T
T
Department of Food Science, Faculty of Agriculture, Kyoto University, Japan.
Kajiura
H
H
Fukuoka
S
S
Kido
K
K
Semba
T
T
Iwai
K
K
D000818:Animals; D000906:Antibodies; D001646:Bile / Q000502:physiology; D002364:Caseins / Q000494:pharmacology; D004044:Dietary Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D004386:Duodenum / Q000187:drug effects; D006133:Growth Substances; D007158:Immunologic Techniques; D036341:Intercellular Signaling Peptides and Proteins; D007768:Lactalbumin / Q000494:pharmacology; D008297:Male; D010047:Ovalbumin / Q000494:pharmacology; D010179:Pancreas / Q000187:drug effects / Q000201:enzymology*; D010187:Pancreatic Hormones; D010189:Pancreatic Juice / Q000502:physiology; D010446:Peptide Fragments / Q000276:immunology / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D014357:Trypsin / Q000378:metabolism / Q000494:pharmacology*; D014359:Trypsin Inhibitor, Kazal Pancreatic / Q000276:immunology / Q000494:pharmacology
D000906:Antibodies; D002364:Caseins; D004044:Dietary Proteins; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D010187:Pancreatic Hormones; D010446:Peptide Fragments; C504705:Spink1 protein, rat; D014359:Trypsin Inhibitor, Kazal Pancreatic; D010047:Ovalbumin; D007768:Lactalbumin; D014357:Trypsin