[Reduction of 5alpha-dehydrotestosterone in sex steroid target cells--catabolism or directed biotransformation into hormones?].

Based on analysis of the published experimental data, we propose a hypothetical mechanism of action of two androgens, 5 alpha-androstane-3 alpha,17 beta-diol (3 alpha-diol) and 5 alpha-androstane-3 beta,17 beta-diol (3 beta-diol), which are produced when 5 alpha-dihydrotestosterone (DHT) is reduced in sex steroids target cells. The mode of action of these diols as regulatory factors assumes that the androgens possess autocrine, paracrine, and endocrine action that differs from the action of DHT in animals and man and do not merely represent catabolites or metabolites capable of controlling the level of true androgenic hormone DHT. It is proposed that both diols should be classified as parahormones.