Abstract
This report presents endocrine data on Ro 5-2537, a synthetic, nonsteroid, phenanthrene derivative which possesses antiandrogenic, progestational, and very weak anti-estrogenic properties. Ro 5-2537 antagonizes both endogenous and exogenous androgen in the rat at dosages which, when given alone to the castrate rat, show no androgenicity. The compound has no significant uterotrophic activity, is not antigonadotrophic, and does not antagonize the antigonadotrophic effects of testosterone. (Endocrinology76:1062, 1965)