Is the metabolism of testosterone to 5 alpha-dihydrotestosterone required for androgen action in the skin?
The assumption that the metabolism of testosterone to 5 alpha-dihydrotestosterone (5 alpha-DHT) is required for androgen action in the skin was investigated by studying the uptake and metabolism of testosterone by skin and other tissues of the rat in vivo. The skin resembled the classical androgen target organs in the uptake and retention of radioactivity, but the proportions of the steroids present were markedly different. In the ventral prostate most of the testosterone was metabolized, mainly to 5 alpha-DHT, after only 20 min. In the skin testosterone was always the predominant steroid identified and androstenedione, 5 alpha-DHT, 5 alpha-androstane-3 alpha, 17 beta-diol, androsterone and 5 alpha-androstane-3 beta, 17 beta-diol were only present in much smaller quantities, even after 5 h. Hypophysectomy, known to reduce the response of the sebaceous glands to testosterone in the rat, did not alter the steroid composition in the classical target organs, the preputial glands, or the plasma, but in the skin it increased testosterone metabolism without altering the levels of 5 alpha-DHT or the 5 alpha-androstane-diols. These results suggest that the 5 alpha-reduction of testosterone to 5 alpha-DHT may not be so important in the skin, or at least in the sebaceous glands, as it is in the prostate.
D000818:Animals; D013196:Dihydrotestosterone / Q000378:metabolism*; D007016:Hypophysectomy; D008297:Male; D011467:Prostate / Q000378:metabolism; D051381:Rats; D012627:Sebaceous Glands / Q000378:metabolism; D012867:Skin / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism*; D013997:Time Factors
D013196:Dihydrotestosterone; D013739:Testosterone