In vitro studies on the inhibition of testosterone synthesis in the human testis by atamestane

In review of the well established clinical results of the deprivation of androgens through orchiectomy in prostatic cancer the structural similarities of 4-androsten-3,17-dione and atamestane (1-methyl-ADD), we studied the influence of 1-methyl-ADD on the conversion of 4-androsten-3,17-dione to testosterone by the 17β-hydroxysteroid reductase enzyme in human testicular tissue. Our studies, presented in this manuscript , demonsrate that 1-methyl-ADD is a competitive inhibitor of 4-androsten-3,17-dione in its reduction to testosterone by the 17β-hydroxysteroid reductase enzyme in the human testis.