Effects of androgen on transient endogenous spleen colonies and other hemopoietic stem cells in mice.

To clarify the effects of androgen on hemopoiesis in mice, we investigated changes in hemopoietic stem cells at various stages of differentiation after injection of 19-nandrolone decanoate (19-ND). 19-ND induced (a) a marked increase in the population of CFUe, especially in the spleen, and (b) a less significant increase in the number of CFUs, GM-CFC, and BFUe. The number of endogenous spleen colonies developed transiently on day 4 after irradiation (TE-CFU) increased significantly, and the initiation and induction of erythropoietic maturation was enhanced. Growth of the pluripotent stem cells (CFUs) assessed by endogenous spleen colony formation was influenced more than was the population size. Production of erythropoietin (Ep) in mice was not affected by the treatment with 19-ND. These results indicate that 19-ND affects mature precursors in erythroid cell lineage rather than pluripotent stem cells and that the effect is unlikely to be induced through an increase in the production of Ep.