EPO leads to phosphorylation of Akt and eNOS. CD34⁺ EPCs were treated with EPO (50 mU/mL) for 0, 5, 15, or 60 minutes as indicated before lysing the cells, running an SDS-PAGE, and transferring to PVDF. (A) The membranes were probed with an antibody against Akt phosphorylated at serine 473 or total Akt. Shown is one of 2 experiments. (B) Mean ± SD of the densitometric analysis of the bands from 2 different experiments. All data are normalized to the average ratio of phosphorylated Akt over total Akt in the 0 minute of exposure lane. *P < .001 compared with the 0 minutes of exposure. (C) The membranes were probed with an antibody against eNOS phosphorylated at serine 1177 or total eNOS. Shown is 1 of 2 experiments. (D) Mean ± SD of the densitometric analysis of the bands from 2 different experiments. All data are normalized to the average ratio of phosphorylated eNOS over total eNOS in the 0 minute of exposure lane. *P < .003 compared with 0 minutes of exposure.