Metabolism of Androgens by Isolated Human Hair Follicles

The study investigated the in vitro metabolism of androgens in isolated male human hair follicles from the scalp, beard, and pubic areas. Testosterone was primarily converted to androstenedione, 5α-dihydrotestosterone, 5α-androstanedione, and androsterone, with the most intensive formation of 5α-dihydrotestosterone in beard follicles. Dehydroepiandrosterone (DHA) was mainly metabolized to 5-androstene-3β,17β-diol, 7α-hydroxy-DHA, androstenedione, and 5α-androstanedione, with limited sulphoconjugation. The metabolism of DHA was more intensive in hair follicles than in human skin and was altered in follicles from balding individuals. DHA inhibited glucose-6-phosphate-dehydrogenase activity in hair follicles, and two dihydrotestosterone-binding components were identified in the hair follicle cytosol.