AJP - Gastrointestinal and Liver Physiology, Vol 241, Issue 2 143-G149, Copyright © 1981 by American Physiological Society
Autoregulation of gastric blood flow and oxygen uptake
L. Holm-Rutili, M. A. Perry and D. N. Granger
The purpose of this study was to determine whether the ability of the
stomach to autoregulate blood flow and oxygen uptake is altered by
sympathetic denervation. Blood flow, oxygen extraction, local arterial
pressure, and venous pressure were continuously monitored in
sympathetically innervated and denervated autoperfused dog stomach
preparations. As perfusion pressure was reduced in increments from 120 to
20 mmHg in innervated preparations, blood flow and oxygen uptake decreased
while oxygen extraction and vascular resistance increased. Reductions in
perfusion pressure in denervated preparations resulted in a decrease in
blood flow, oxygen uptake, and vascular resistance, whereas oxygen
extraction increased. The ability of the stomach to regulate blood flow and
oxygen uptake was significantly improved after denervation, i.e., vascular
resistance decreased and oxygen uptake remained relatively constant when
arterial pressure was reduced. Oxygen uptake in denervated stomachs was
generally higher than that in innervated stomachs. Autoregulation of
gastric blood flow therefore appears to be improved by denervation. The
better autoregulation observed after denervation may result either from a
reduction in sympathetic tone and/or the increase in gastric oxygen demand.
