Cooperative erythropoietic assay of several steroid metabolites in polycythemic mice.

A blinded cooperative assay of several androstane and pregnane steroid metabolites has been carried out in order to determine whether 5beta-H derivatives are as active as testosterone in stimulating in vivo erythropoiesis. The steroids tested were: testosterone, 5alpha-dihydrotestosterone, 5beta-dihydrotestosterone, 5beta-pregnane-3,20-dione, 3alpha-dihydroxy-5beta-pregnane-11,20-dione and 3beta-hydroxy-5beta-pregnan-20-one. The incorporation of radioactive iron into newly formed red cells in exhypoxic polycythemic mice was used to compare the effects of the steroids. Testosterone and 5alpha-dihydrotestosterone both produced significant increases in 59Fe incorporation. 5beta-dihydrotestosterone, 5beta-pregnane-3,20-dione, 3alpha-hydroxy-5beta-pregnane-11,20-dione and 3beta-hydroxy-5beta-pregnan-20-one were all devoid of significant erythropoietic activity in polycythemic mice in almost all instances. Thus, under the conditions chosen, this study failed to demonstrate that 5beta-steroids increase radioactive iron incorporation in red cells of exhypoxic polycythemic mice.