Identification of Œstradiol-17 _β Testosterone and its Precursors from Scylliorhinus stellaris Testes

Abstract

SINCE its first isolation by Laqueur et al. ¹ in 1935 from tissue of steer testis, testosterone has been obtained from some species of mammals only, namely, horse and man, by Ruzicka et al. ^2,3. Furthermore, Brady⁴, by in vitro experiments on the biosynthesis of testosterone from ¹⁴C-acetate, indicated that testosterone is probably the androgenic testicular hormone in two additional species, rabbit and hog. Androgenic substances of non-mammalian vertebrates are still unknown. On the other hand, œstradiol-17β has been found to be the œstrogenic hormone not only in mammals but also in the elasmobranch Squalus suckleyi ⁵, in the lungfish Protopterus annectens ⁶, in birds⁷ and in the starfish Pisaster ochraceus ⁸. The investigation of the androgenic material in non-mammalian vertebrates seems therefore necessary to fill this gap, and is of obvious evolutionary importance.