Figure 2.

EPO prevents apoptosis of P19 cells. (A) Cells were serum-deprived for 24 h and apoptotic nuclei were counted after staining with H33258. EPO (1 unit/ml) was added as a 24-h pretreatment (EPO pre) and then removed, or added immediately after serum deprivation (EPO post). (B) Dose–response of the effect of a 24-h pretreatment with EPO on apoptosis induced by subsequent serum and EPO deprivation. (C) Time course of apoptosis induced by serum deprivation in control or 24-h EPO-pretreated cells. (D) Effect of EPO on thymidine incorporation in the presence or absence of serum. (Data represent mean ± SD. *, P < 0.05; **, P < 0.01 indicate significant differences as compared with serum deprivation without EPO treatment.)