LECs were exposed to sodium arsenite (40 μM) in the absence or presence of NAC (5, 10 or 20 mM) or GSH (5, 10 or 20 mM) (pH adjusted to 7.6). NAC and GSH were added 1 h before the addition of sodium arsenite. LECs were also treated with various concentrations of NAC and GSH alone. After treatment for 24 h, cells were lysed and whole cell lysate was prepared. Effects of NAC (A) and GSH (C) on protein expression profiles of seven proteins in basal and arsenite-treated cells were assessed by 2-DE analyses and shown in montage view. (B, D) Western-blot analyses for the detection of Bax and procaspase 3, using anti-Bax and anti-procaspase 3 antibodies respectively and monoclonal anti-β-actin antibody to monitor the loading difference. (B) The corresponding Western-blot analysis of (A). (D) The corresponding Western-blot analysis of (C). The results are representative of three independent experiments.