Effects of EPO treatment (3 times a week [arrows]) on the relative increase in circulating P-selectin and circulating E-selectin levels in men undergoing phlebotomy (P) on days 8 and 15.

Subjects (n = 30) received bolus infusions of either 500 U/kg of EPO (black squares; n = 10), 100 U/kg of EPO (open triangles; n = 10), or placebo (open circles; n = 10). Data are mean ± SEM.