Canine pancreatic responses to intestinally perfused proteins and protein digests
Meyer, J.H.; Kelly, G.A.
American Journal of Physiology 231(3): 682-691
1976
ISSN/ISBN: 0002-9513 PMID: 970450 Document Number: 104669
Pancreatic bicarbonate and protein secretory responses to intestinally perfused proteins or digests of proteins were estimated in dogs with chronic gastric and pancreatic fistulae when luminal pancreatic protease concentrations were reduced to undetectable amounts. Amino acids were estimated in protein digests and other indirect methods were used to assess the composition of the digest mixtures. Of 5 undigested proteins, none evoked more pancreatic secretion than a control perfusion with saline. Peptic digestion of the proteins converted 4 of them to polypeptides that were potent stimuli of a pancreatic juice similar in HCO3-:protein ratios to that evoked by luminal amino acids. Dialysed peptic digests of one of the proteins, bovine serum albumin (BSA), retained potency. Digestion of BSA with endogenous or exogenous pancreatic proteases converted the protein to a stimulus about equipotent with the peptic digest, though the composition of the pancreatic digests differed markedly from that of the peptic digests. It is concluded that luminal peptides of 4 or more amino acids can stimulate the pancreas and during protein feeding many luminal products may evoke pancreatic secretion.