摘要
Oxidative stress has been implicated in the pathophysiology of liver injury during xenobiotic and alcohol metabolism, ischemia/reperfusion injury. In this study we examined if ethanol acted as a pro-oxidant making cells become more sensitive to tert-butylhydroperoxide (tBH) killing. Cell viability was determined in a rat hepatoma cell line (FTO2B) and rat primary hepatocytes in culture in the presence or absence of ethanol pretreatment. To elucidate the contribution of labile iron, deferoxamine (DF, an iron chelator) or lipid free radicals, N,N-diphenyl-p-phenylenediamine (DPPD, a lipid scavenger) were added to the ethanol tBH co-treatment. The levels of glutathione (GSH) and glutathione disulfide (GSSG) in the hepatocytes were also measured. Ethanol treatment (both pretreatment and co-treatment during the 3-hr tBH exposure) increased cell killing dramatically in both FTO2B cells and primary rat hepatocytes. Both DF and DPPD decreased ethanol-enhanced tBH cell killing in hepatocytes. These results demonstrated that co-treatment of FTO2B cells and primary rat hepatocytes with ethanol and tBH increased cell killing. The GSH level was dramatically reduced while GSSG level rose. Both DFP and DPPD reversed or protected the cells from this insult, indicating that ethanol was a pro-oxidant.
Oxidative stress has been implicated in the pathophysiology of liver injury during xenobiotic and alcohol metabolism, ischemia/reperfusion injury. In this study we examined if ethanol acted as a pro-oxidant making cells become more sensitive to tert-butylhydroperoxide (tBH) killing. Cell viability was determined in a rat hepatoma cell line (FTO2B) and rat primary hepatocytes in culture in the presence or absence of ethanol pretreatment. To elucidate the contribution of labile iron, deferoxamine (DF, an iron chelator) or lipid free radicals, N,N-diphenyl-p-phenylenediamine (DPPD, a lipid scavenger) were added to the ethanol tBH co-treatment. The levels of glutathione (GSH) and glutathione disulfide (GSSG) in the hepatocytes were also measured. Ethanol treatment (both pretreatment and co-treatment during the 3-hr tBH exposure) increased cell killing dramatically in both FTO2B cells and primary rat hepatocytes. Both DF and DPPD decreased ethanol-enhanced tBH cell killing in hepatocytes. These results demonstrated that co-treatment of FTO2B cells and primary rat hepatocytes with ethanol and tBH increased cell killing. The GSH level was dramatically reduced while GSSG level rose. Both DFP and DPPD reversed or protected the cells from this insult, indicating that ethanol was a pro-oxidant.
