The role of protein glutathionylation in acetaminophen (APAP)-induced liver injury was investigated in this study. A single oral gavage dose of 150 or 300 mg/kg APAP in B6C3F1 mice produced increased serum ALT and AST levels and liver necrosis in a dose-dependent manner. The ratio of reduced (GSH) to oxidized (GSSG) glutathione was decreased in a dose-dependent manner, suggesting that APAP produced a more oxidizing environment within the liver. Despite the increased oxidation state, the level of global protein glutathionylation was decreased at 1 hour and continued to decline through 24 hours. Immunohistochemical localization of glutathionylated proteins showed a complex dynamic change in the lobule zonation of glutathionylated proteins. At 1 hour after APAP exposure, the level of glutathionylation decreased in the single layer of hepatocytes around the central veins but increased mildly in the remaining centrilobular hepatocytes. This increase correlated with the immunohistochemical localization of APAP covalently bound to protein. Thereafter, the level of glutathionylation decreased dramatically over time in the centrilobular regions with major decreases observed at 6 and 24 hours. Despite the overall decreased glutathionylation, a layer of cells lying between the undamaged periportal region and the damaged centrilobular hepatocytes exhibited high levels of glutathionylation at 3 and 6 hours in all samples and in some 24 hour samples that had milder injury. These temporal and zonal pattern changes in protein glutathionylation after APAP exposure indicate that protein glutathionylation may play a role in protein homeostasis during APAP-induced hepatocellular injury.
- Received September 14, 2011.
- Revision received October 28, 2011.
- Accepted October 31, 2011.
- The American Society for Pharmacology and Experimental Therapeutics