Figure 2.

Acetaminophen (APAP) augments lipopolysaccharide (LPS)–induced apoptosis in rat liver. Rats were administered phosphate-buffered saline (PBS) vehicle or 5 mg/kg LPS, followed by PBS vehicle or 200 mg/kg APAP 1 hour later. Livers were harvested at 6 hours for indicated determinations. A: Sections representative of each group stained with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL; green) and counterstained with DAPI (blue) to mark nuclei were imaged by fluorescence microscopy. Red boxed area is magnified (inset) to show TUNEL-positive hepatocyte. Bar graph shows quantification of TUNEL-stained cells. B: Western blot analysis shows hepatic procaspase-3 and cleaved caspase 3 (Cas-3) expression. Bar graph shows densitometric quantification of cleaved caspase 3 relative to β-actin. C: Caspase 3 activity. D: Western blot analysis shows hepatic total c-Jun N-terminal kinase (T-JNK; isoforms 1 and 2) or phosphorylated JNK1 and JNK2 (P-JNK1 and P-JNK2, respectively). Bar graph shows relative expression of P-JNK1 versus T-JNK1 and P-JNK2 versus T-JNK2. E: Dihydroethidium (DHE)–treated liver sections demonstrate the magnitude of oxidative stress in the treatment groups relative to control. Bar graph shows quantification of the red fluorescent hydroxylated ethidium produced because of oxidation of DHE by superoxide. F: Hepatic glutathione (GSH) levels in the various groups. For all experiments, n = 6 to 8 per group. ∗P < 0.05, ∗∗P < 0.01, and ∗∗∗P < 0.001 versus control or as indicated. Scale bars = 100 μm (A and E). MFI, mean fluorescence intensity.