AJP - Gastrointestinal and Liver Physiology, Vol 258, Issue 2 316-G319, Copyright © 1990 by American Physiological Society
CGRP stimulates the release of pro-somatostatin-derived peptides from the gastric fundus
N. W. Bunnett, W. S. Helton, H. T. Debas and J. W. Ensinck
Department of Surgery, University of California, San Francisco 94143.
Calcitonin gene-related peptide (CGRP) stimulates release of peptides
derived from pro-somatostatin (Pro-S) into the general circulation. The
purpose of this investigation was to elucidate the origin and molecular
heterogeneity of Pro-S-derived peptides secreted in response to CGRP.
Catheters were placed into the vena cava and veins draining the gastric
fundus and corpus, antrum, and small intestine of anesthetized pigs. Human
CGRP I was infused into the descending aorta at 0.2, 0.4, 0.8, and 1.6
micrograms.kg-1.h-1 for consecutive 30-min intervals. Blood was collected
from the venous catheters after each period. S-28 was separated from Pro-S,
S-14, and S-13 by immunoaffinity chromatography and peptides were
quantified by radioimmunoassay. CGRP primarily evoked release of peptides
measured collectively as Pro-S, S-14, and S-13 into venous blood draining
the fundus and corpus, and concentrations were significantly elevated above
basal at 0.8 and 1.6 micrograms.kg-1.h-1 CGRP (P less than 0.05). Basal
concentrations of S-28, Pro-S, S-14, and S-13 in blood from the antrum and
small intestine were not significantly elevated by CGRP. In conclusion,
CGRP stimulated release of Pro-S-derived peptides from the gastric fundus
and corpus but not from the antrum or small intestine.
