[The effect of sodium-4-[2-(2,3-dimethyl-4-[1-(4- isobutylphenyl)ethoxy]benzolamino)phenoxy] butyrate (ONO-3805) and antiandrogenic agents on the rat accessory sex organs].

The effects of sodium-4-[2-(2,3-dimethyl-4-[1-(4-isobutylphenyl) ethoxy]benzolamino)phenoxy]butyrate (ONO-3805), newly developed as a non-steroidal 5 alpha-reductase inhibitor, on rat accessory sex organs was compared with chlormadinone acetate (CMA) and non-steroidal antiandrogen, flutamide (FLU). ONO-3805 demonstrated excellent antiandrogenic activity which was similar to that of CMA in reducing the accessory sex organ weight. Moreover this agent did not show any significant effects on the serum testosterone level, but CMA and FLU changed it significantly. We previously reported the androgenic activity of antiandrogen (CMA, FLU, AA560, cyproterone acetate, medroxy progesterone, estrogen), but ONO-3805 is free of androgenic activity.