AJP - Gastrointestinal and Liver Physiology, Vol 252, Issue 5 648-G653, Copyright © 1987 by American Physiological Society
Glucagon increases hepatic oxygen supply-demand ratio in pigs
S. Gelman, E. Dillard and D. A. Parks
The present study was performed on eight young pigs to test the hypothesis
that glucagon increases hepatic oxygen supply to a greater extent than
hepatic oxygen uptake, providing a better hepatic oxygen supply-demand
relationship. The experiments were performed under pentobarbital sodium
anesthesia and controlled ventilation. Splanchnic blood flow was studied
using radioactive microspheres. Glucagon was administered in doses of 1 and
5 micrograms X kg-1 X min-1. During glucagon infusion, hepatic arterial
blood flow substantially increased, splenic and pancreatic blood flows
increased moderately, while stomach and intestinal blood flows, as well as
portal blood flow did not change significantly. Shunting of both 9- and
15-micron spheres through preportal tissues did not change significantly.
Oxygen content in arterial or portal venous blood did not change
significantly, while it increased in hepatic venous blood by 30%. There
were no differences in the effects between the doses of glucagon
administered. There was no correlation found between changes in hepatic
oxygen supply and cardiac output or blood pressure. The changes observed
during glucagon administration resulted in an increase in oxygen delivery
to the liver and hepatic oxygen supply-uptake ratio.
