AJP - Gastrointestinal and Liver Physiology, Vol 246, Issue 4 401-G410, Copyright © 1984 by American Physiological Society
Evidence for cardiac volume-receptor regulation of feline jejunal blood flow and fluid transport
H. Sjovall, S. Redfors, B. Biber, J. Martner and O. Winso
The aim of the study was to investigate the role of cardiac
mechanoreceptors in the reflex regulation of intestinal blood flow and
fluid transport. Feline cardiac mechanoreceptor activity was modified with
two noninvasive techniques: positive-pressure ventilation (PPV) and
inspiratory resistance breathing (IRB). A jejunal segment with intact
vascular and nervous supply was isolated and exposed to cholera toxin as a
model for intestinal secretion. The results revealed that PPV induced a
pronounced intestinal vasoconstriction and a marked inhibition of choleraic
secretion. IRB had the opposite effects. The responses were well correlated
with changes in central blood volume and either markedly reduced or
abolished by vagotomy, intestinal alpha-adrenoreceptor blockade, or
postganglionic mesenteric denervation. The results indicate that cardiac
mechanoreceptors with vagal afferents may mediate the observed reflex
responses, and hence this receptor station may be of importance in the
normal reflex control of intestinal hemodynamics and fluid transport.
