Effect of androgen action on cell viability and apoptosis with or without Dox in H9c2 Cells. H9c2 cells were pretreated with or without flutamide or LY294002 for 1 h before testosterone (T) administration. After 24 h, cells were coincubated with Dox for 24 h and then analyzed. A, Cell viability after Dox treatment for 24 h in H9c2 cells. Cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt assay. Values are relative change to control value and expressed as means ± sem. *, P < 0.05; **, P < 0.01, n = 6 in each group. B, Apoptotic cells after Dox treatment of H9c2 cells. Upper panel, Representative photomicrographs of TUNEL-positive cells. The nuclei of apoptotic cells were determined by TUNEL staining (green), and total nuclei were demonstrated by DAPI staining (blue). Lower panel, The percentage of TUNEL-positive cells in three random fields. Values are relative change to control value and expressed as means ± sem. *, P < 0.05; **, P < 0.01, n = 4 in each group.