[Hydroxylation of testosterone and 5alpha-dihydrotestosterone--isolation of 2alpha-hydroxytestosterone (author's transl)].

The hydroxylation at C-2 of testosterone and 5alpha-dihydrotestosterone is measured by isolation of HTO after incubating "metabolically labile" tritium labeled steroids with the enzymes. After hydroxylation of testosterone in rat liver 2alpha-hydroxytestosterone was isolated and identified by gaschromatography and mass spectra.