On the mechanism of erythropoietin-induced differentiation. XIV. The apparent effect of etiocholanolone on initiation of erythropoiesis.

Etiocholanolone, when tested in normal mice or in mice that have been out of an hypoxic atmosphere for only a few days, stimulates erythropoiesis, but appears to have no effect on erythropoiesis when tested in plethoric mice that have very low residual red cell formation. The steroid, similarly, stimulates hemoglobin synthesis by marrow cells in culture if they are from normal mice, but has no effect on cells from transfused mice. Out data suggest that 5 beta-H androstane and pregnane derivatives do not have a primary action on the induction of erythropoiesis, but act on cells that are already differentiated.