Control of human sebocyte proliferation in vitro by testosterone and 5-alpha-dihydrotestosterone is dependent on the localization of the sebaceous glands.

Androgens stimulate the activity of sebaceous glands in vivo. In this study the in vitro effect of androgens on the proliferation of cultured human sebocytes derived from facial and non-facial skin were assessed. Human sebocytes from sebaceous glands isolated from the face and the upper and lower legs of five individuals were cultured in vitro with or without testosterone or 5-alpha-dihydrotestosterone (5 alpha-DHT) at different concentrations (10(-11)-10(-5) M). Cell proliferation was assessed in 96-well culture plates using a fluorometric assay. Testosterone and 5 alpha-DHT stimulated the proliferation of human facial sebocytes in a significant dose-dependent manner. In our system 5 alpha-DHT exhibited the strongest effect; on the contrary, the proliferation of non-facial sebocytes was inhibited by testosterone, whereas 5 alpha-DHT enhanced their growth. The stimulatory effect of 5 alpha-DHT was more prominent on facial than on non-facial sebocytes. These results provide first evidence that the effect of testosterone and 5 alpha-DHT on the proliferation of cultured human sebocytes may depend on the localization of the sebaceous glands at different skin regions.