androstane-3-17-dione--(5alpha)-isomer and Alopecia

In androgen target tissues, testosterone undergoes extensive biotransformation to 5 alpha-dihydrotestosterone which in turn is metabolized into 5 alpha-androstane-3 alpha,17 beta-diol and 5 alpha-androstane-3 beta,17 beta-diol. From studies mainly in the prostate, it has been shown that 5 alpha-androstane-3 beta, 17 beta-diol can be further converted to 5 alpha-androstane-3 beta,6 alpha(beta)/7 alpha(beta),17 beta-triols. The present studies show that among the metabolites of 5 alpha-androstane-3 beta,17 beta-diol in scalp homogenates, three were isolated by thin-layer chromatography and identified against standard steroids: 5 alpha-dihydrotestosterone, epiandrosterone, and 5 alpha-androstanedione. Another peak was observed near the origin with a greater polarity than 5 alpha-androstane-3 beta,17 beta-diol. The chromatograms obtained by incubating 5 alpha-androstane-3 beta,17 beta-diol with scalp and prostate homogenates are similar, and it is known that the polar metabolites in the prostate are 5 alpha-androstane-3 beta,6 alpha(beta)/7 alpha(beta),17 beta-triols, suggesting that these steroids are formed in both tissues. In addition, the similarity of chromatograms and mass spectra, obtained when 3 beta-diol polar metabolite(s) and authentic 5 alpha-androstane-3 beta,7 beta,17 beta-triol were subjected to GC/MS, confirms this hypothesis. The dependence of the formation of polar metabolites on the substrate (5 alpha-androstane-3 beta, 17 beta-diol) concentration (50 nM-1.3 microM) was studied and resulted in saturation and linear Lineweaver plots from both bald and hairy areas of the scalp.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Alopecia; Androstane-3,17-diol; Androsterone; Dihydrotestosterone; Etiocholanolone; Gas Chromatography-Mass Spectrometry; Humans; Kinetics; Male; Scalp