RhEPO inhibits H
-induced apoptosis in isolated cardiomyocytes. Neonatal rat cardiomyocytes were treated with PBS as a control or with H2O2 (150 μM) for 60 minutes in the 24 h presence or absence of rhEPO produced from transduced fibroblasts (12 mIU/ml). (A) Annexin V/PI staining: (a) Representative density profile (percentage of cells in each quadrant is indicated); (b) Quantitative analysis, showing that EPO attenuated cardiomyocyte apoptosis. (B) DAPI staining: (a) representative photomicrographs (arrows show apoptotic cardiomyocyte nuclei (chromatin condensation and nuclei fragmentation); (b) quantitative analysis, as represented by relative apoptotic nuclei counts.