Metabolism of 17 alpha-methyl-5 beta-dihydrotestosterone in the rabbit.

17 alpha-Methyl-5 beta-androstane-3 alpha,17 beta-diol together with the hydroxylated metabolites 17 alpha-methyl-5 beta-androstane-1 beta,3 alpha,17 beta-triol, 17 alpha-methyl-5 beta-androstane-3 alpha,12 beta,17 beta-triol, 17 alpha-methyl-5 beta-androstane-3 alpha,16 alpha,17 beta-triol and 17 alpha-methyl-5 beta-androstane-3 alpha,16 beta,17 beta-triol were isolated and identified in the urine of rabbits orally dosed with 17 alpha-methyl-5 beta-dihydrotestosterone. Biotransformations differ from the 5 alpha-series where hydroxylation occurred at C-6 and C-15. In both series, the C-3 equatorial epimer was the major urinary excretion product among the non-hydroxylated metabolites. The 5 beta-compound was more resistant to metabolic hydroxylation than the 5 alpha-compound. No evidence for epimerization at the C-17 position was observed.