Erythropoietin acts on:

Normal duration of erythropoiesis = 7- 9 days Under influence of erythropoietin = 5- 6 days EPO acts on earlier precursors i.e. Formation of burst forming units formation of proerythroblast It has been determined that the impoant effect of erythropoietin is to stimulate the production of proerythroblast from hematopoietic stem cells in the bone marrow. In addition, once the proerythroblasts are formed, the erythropoietin causes these cells to pass more rapidly through the different erythroblastic stages than they normally do, fuher speeding up the process Page 488, CH 33. :