Effects of volatile anesthetics on the calcium ionophore A23187-mediated alterations in hepatic flow and metabolism in the perfused liver in fasted rats.

Alterations in intracellular calcium homeostasis have been implicated in heptic injury. Volatile anesthetics modulate the homeostasis of intracellular calcium. The effects of volatile anesthetics on the hemodynamic and metabolic alterations induced by the calcium ionophore A23187 were studied using isolated liver perfusion in fasted rats. The liver was isolated from 24 hr-fasted male Sprague-Dawley rats, and perfused through the portal vein at a constant pressure of 1.2 kPa in a recirculating perfusion-aeration system. Halothane, isoflurane and sevoflurane were administered at 2%, 3% and 4.4%, respectively. All volatile anesthetics maintained basal hepatic flow, reduced oxygen consumption, and transiently enhanced net lactate production. A23187 at initial concentrations of 0.8 to 3.2 microM decreased hepatic flow and oxygen consumption in a dose-dependent manner, and enhanced lactate production. All anesthetics significantly attenuated the decreases in hepatic flow and oxygen consumption after administration of A23187 at 1.6 microM. None of the anesthetics significantly influenced the A23187-induced enhancement of net lactate production. Volatile anesthetics may attenuate the hepatic vasoconstriction and oxygen debt induced by intracellular calcium overload.