ACTION OF A NON-STEROID ANTI-ANDROGEN, RU-23908, IN PERIPHERAL AND CENTRAL TISSUES

RU 23908 (5,5-dimethyl-3-[4-nitro-3-(trifluoromethyl)phenyl]-2,4-imidazolidinedione) is a non-steroid anti-androgen with potent peripheral and central activity. In the rat, it inhibits androgen-induced prostate weight increase and negative androgen-dependent gonadotrophin feedback giving rise to an increase in LH and in testosterone. Association with a pituitary inhibitor counteracts this increase and enables full expression of its anti-androgen potential. Its mechanism of action would seem to be comparable to that of steroid anti-androgens in that it is able to inhibit effectively testosterone binding to the cytoplasmic androgen receptor after short but not long incubation times, i.e. it associates and dissociates very rapidly from this receptor thus preventing the full response of the endogenous hormone by transiently occupying available binding sites. © 1979.