Androgen biosynthesis by testicular tissue of the desert rodents, Acomys cahirinus and Gerbillus dasyurus

Androgen biosynthesis was investigated in the desert rodents, Acomys cahirinus and Gerbillus dasyurus. In these experiments, radioactive substrates were incubated with testicular homogenates and the metabolites formed were identified. The accumulation of 5 ene 3β hydroxysteroids suggested that the biosynthesis proceeded preferentially by the 4 ene route. This was confirmed by double label experiments where [³H]5 ene 3β hydroxysteroids and [¹⁴C]4 en 3 oxosteroids were employed. The preferred route for the production of the major androgens appears to be pregnenolone → progesterone → 17α hydroxy progesterone → androstenedione → testosterone. In addition, these species were characterized by enhanced activity of 20α hydroxysteroid oxidoreductase and low activity of 17β hydroxysteroid oxidoreductase, a phenomenon also observed in the laboratory rat and mouse acclimatized to a hot environment. Some parameters of desert ecology are briefly described.