Using the isolated perfused rat liver, we investigated the relationship of
glutathione (GSH) with
reactive oxygen species (ROS) generation and liver cell damage during
ischemia/reperfusion in normal and GSH-depleted conditions.
Lucigenin-enhanced chemiluminescence was used as a sensitive index of tissue ROS generation. After 30 minutes of equilibration, livers were subjected to global
ischemia for various times (60 or 90 minutes) and then reperfused for another 120 minutes. Intracellular ROS levels increased sharply at the onset of reperfusion and then declined slowly. After 30 to 60 minutes of reperfusion, ROS levels started to increase progressively in a linear fashion. However, sinusoidal
glutathione disulfide release did not increase during reperfusion in the same livers, suggesting that intracellular ROS generation is too low to cause a significant increase in GSH oxidation. Pretreatment with
phorone (300 mg/kg intrapentoneally [ip]), which reduced hepatic GSH by 90%, did not cause any difference in intracellular ROS generation compared with the control livers. There were also no significant differences in
lactate dehydrogenase and
thiobarbituric acid reactive substances (
TBARS) release between the control and
phorone-treated livers during reperfusion after various times of
ischemia. These data indicate that ROS generation in the normal isolated perfused liver during
ischemia/reperfusion is extremely low and intracellular GSH does not serve as a major intracellular defense system against such a low oxidative stress.