Figure 1.

Cytotoxicity and chemical modification of cellular proteins during treatment of cells with 1,4-NQ, with or without Na₂S₄. (A,B) Primary mouse hepatocytes were exposed to 1,4-NQ with or without 10 (A) or 100 (B) µM Na₂S₄ for 24 h. Cell viability was assessed with the MTT assay. Each value is the mean ± standard error for three independent experiments. *P < 0.05 and **P < 0.01, compared with the control. C, D: Primary mouse hepatocytes were exposed to 1,4-NQ, with or without 10 (C) or 100 (D) µM Na₂S₄ for 1 h. Covalent modification of cellular proteins by 1,4-NQ was detected by western blotting using an anti-1,4-NQ antibody (upper), proteins were detected following SDS-PAGE by Coomassie Brilliant Blue staining (middle) and intensities of modified protein bands were calculated with Multi Gauge software (lower). Representative data are shown from two independent experiments.