AJP - Gastrointestinal and Liver Physiology, Vol 251, Issue 2 280-G284, Copyright © 1986 by American Physiological Society
Vasoactive intestinal peptide may participate in the vasodilation of the dog hepatic artery
G. Varga, J. Z. Kiss, M. Papp and E. S. Vizi
The possible direct action of vasoactive intestinal peptide (VIP) on dog
hepatic arterial wall or on the noradrenergic innervation of the artery was
investigated in vitro. In addition, VIP-containing nerve fibers and
terminals were located in the wall of the artery with immunochemical
staining. Direct evidence showed that VIP did not affect the release of
[3H]norepinephrine but reduced the response of the isolated hepatic artery
to electrical field stimulation and exogenous norepinephrine. This suggests
that the effect of VIP is postjunctional on the smooth muscle of the
artery. VIP-containing nerve fibers and varicosities were observed in the
adventitial and medial layer of the arterial wall. These findings strongly
support the hypothesis that vasoactive intestinal peptide is a
physiological mediator of vasodilation in the hepatic artery.
