Fig. 4.

Effect of glutathione peroxidase and selenium on apoptosis and cell cycle arrest produced by a 2-h exposure to doxorubicin in parental and Gpx-1 knockout cardiac fibroblasts examined 96 h following the initiation of drug treatment. Apoptosis was evaluated by TUNEL assay; cell cycle progression of cells initially in log-phase growth was evaluated by flow cytometry. TUNEL positive cells were assessed across the cell cycle and are shown as strand breaks measured on the y-axis quantitated as events on the z axis. These data are representative of at least three separate experiments.