Histological assessment of liver injury (hematoxilin & eosin, H&E), peroxynitrite formation (nitrotyrosine staining) and DNA fragmentation (TUNEL assay) in control animals or mice treated with 300 mg/kg acetaminophen (APAP) for 6 h. Some of the animals received additionally 10 ml/kg saline, 0.65 mmol/kg GSH or 0.65 mmol/kg N-acetylcysteine (NAC) iv 1.5 h after APAP. The representative pictures show extensive centrilobular necrosis, which correlated with the areas of nitrotyrosine staining and TUNEL-positive cells in APAP-treated animals. Both, GSH and NAC treatment improved all parameters with GSH being more effective than NAC. (×100 for all panels)