AJP - Gastrointestinal and Liver Physiology, Vol 248, Issue 2 208-G215, Copyright © 1985 by American Physiological Society
Vasoactive intestinal polypeptide, cholecystokinin, glucagon, and bile-oleate-induced jejunal hyperemia
R. H. Gallavan Jr, M. H. Chen, S. N. Joffe and E. D. Jacobson
The purpose of this study was to evaluate the roles of vasoactive
intestinal polypeptide (VIP), cholecystokinin (CCK), and glucagon in the
local regulation of the lipid-induced intestinal hyperemia. Total blood
flow and the arteriovenous hormone concentration gradient were measured in
isolated jejunal loops of anesthetized dogs with either saline, bile (10%
in normal saline), oleic acid (40 mM in normal saline), or oleic acid and
bile in the lumen. The bile-oleic acid mixture increased both blood flow
(+21 +/- 7%) and VIP release (+118 +/- 7%), while CCK release was
considerably less. There was a transient rise in glucagonlike
immunoreactivity but no change in pancreatic glucagon release. Neither bile
nor oleic acid alone altered either local blood flow or hormone release.
Infusion of VIP into the arterial circulation of the jejunum significantly
reduced vascular resistance (-11 +/- 4%) but at a dose (150 ng . min-1 X
100 g-1) 10 times that released in response to the bile-oleic acid mixture.
This study indicates that oleic acid increases both blood flow and
intestinal hormone production only when present in the lumen in micellar
form and suggests that VIP could play a role in the jejunal vascular
response to fat.
