Abstract
It is well known that norepinephrine causes an increase in hepatic oxygen consumption, as well as hepatic venoconstriction. However, it is not known whether oxygen consumption increases during anaphylactic hepatic venoconstriction. We determined oxygen consumption during hepatic venoconstriction induced by norepinephrine or anaphylaxis in isolated rat livers perfused portally and recirculatingly at constant flow with diluted blood (Hct 12.2%). Oxygen consumption was measured by monitoring continuously the differences in portal and hepatic venous O2 content using the absorption spectrophotometer (ODM-1, Biomedical Science, Kanazawa), the sensors of which were equipped in the inflow and outflow perfusion lines. The hepatic anaphylaxis was induced by an injection of ovalbumin (0.1mg) into the perfusate of the isolated liver derived from the rat sensitized with ovalbumin (1 mg). Hepatic venoconstriction and liver weight loss were similarly observed in response to norepinephrine (0.01∼10 μM) and anaphylaxis. However, the response of oxygen consumption was different between anaphylaxis and norepinephrine; hepatic anaphylaxis caused a decrease in oxygen consumption, while norepinephrine increased oxygen consumption, as reported previously. We conclude that anaphylactic hepatic venoconstriction is accompanied by a decrease in hepatic oxygen consumption in rats. [Jpn J Physiol 55 Suppl:S89 (2005)]
