The Effect of Erythropoietin on Synchronized Rabbit Hemopoietic Tissue in Culture

Synchronized erythroid cell cohorts were cultured for up to 6 days with and without added erythropoietin. The presence of erythropoietin in the medium was found indispensable for the synchronized differentiation and maturation of those cell populations. The appearance, during maturation in vitro, of a soluble cell component that is capable of inducing hemoglobin producation by polysomes isolated from undifferentiated blast cells is described. The same polysomes with their isologous soluble cell component were unable to produce this protein. These results confirm earlier observations made on synchronized rabbit cell populations in vivo.