AJP - Gastrointestinal and Liver Physiology, Vol 264, Issue 1 22-G29, Copyright © 1993 by American Physiological Society
Regulation of secretion of pancreatic spasmolytic polypeptide from porcine pancreas
T. N. Rasmussen, H. Harling, L. Thim, S. Pierzynowski, B. R. Westrom and J. J. Holst
Department of Medical Physiology C, Panum Institute, Rigshospitalet, University of Copenhagen, Denmark.
We studied the neural and hormonal regulation of the secretion of
pancreatic spasmolytic polypeptide (PSP), a potential growth factor, from
isolated perfused porcine pancreas and the pancreatic exocrine secretion of
PSP in response to a meal in young conscious pigs. PSP concentrations in
the pancreatic juice ranged from 1 to 180 micrograms/ml. PSP released to
the venous effluent amounted to 0.4-7% of the total output. Thus PSP is
predominantly an exocrine product. Electrical vagal nerve stimulation
increased PSP output 30-fold. Acetylcholine mimicked the effect of nerve
stimulation, which was inhibited but not abolished by atropine. Both
vasoactive intestinal polypeptide and gastrin-releasing peptide stimulated
PSP secretion. PSP concentration in the juice decreased in response to
secretin and increased after cholecystokinin octapeptide (CCK-8), but both
increased PSP output. In conscious pigs, pancreatic secretion of protein
and PSP increased in parallel. Like pancreatic enzyme secretion, we
conclude that PSP secretion is controlled by parasympathetic mechanisms
that include both cholinergic and peptidergic pathways and by endocrine
mechanisms that may include both secretin and CCK-8.
