The effect of 5 alpha-dihydrotestosterone and 5 beta-dihydrotestosterone on erythropoiesis of the newt, Triturus cristatus carnifex (Laur.).

The erythropoietic effects of 5 alpha-dihydrotestosterone (5 alpha-DHT) and 5 beta-dihydrotestosterone (5 beta-DHT) were compared in the newt, Triturus cristatus carnifex (Laur.). In normal animals, 5 beta-DHT was more active than 5 alpha-DHT in increasing the number of circulating erythrocytes. In animals rendered completely anemic, only 5 beta-DHT was effective. The biochemical parameters of delta-aminolevulinic acid synthase and delta-aminolevulinic acid dehydratase of new basophilic erythroblasts, and incorporation of labeled glycine into heme and globin of new polychromatic erythroblasts were enhanced by 5 beta-DHT. The results are discussed with reference to a direct erythropoietin-independent action of 5 beta-DHT on erythroid stem cells.