To investigate the varying response of the pilosebaceous unit to androgens functional studies were performed on the effects of testosterone and 5 alpha-dihydrotestosterone on cultured human sebocytes derived from different skin regions. In addition, the effect of spironolactone on the proliferation of androgen-stimulated human sebocytes derived from facial skin was evaluated. Testosterone (10(-11) to 10(-5) M), 5 alpha-dihydrotestosterone (10(-11) to 10(-5) M) and spironolactone (10(-12) to 10(-7) M) were added for 10 days as single substances or in combinations to human sebocytes in secondary culture maintained in a serum-free medium. Cell proliferation was assessed using a fluorometric assay. Intracellular lipids were extracted from sebocytes treated with androgens (10(-7) M) for 10 days after confluency. Testosterone inhibited the proliferation of sebocytes derived from the legs with a 50%-inhibitory concentration at 10(-5) M and induced a 50% decrease of intracellular lipids. In contrast, 5 alpha-dihydrotestosterone stimulated the activity of leg sebocytes with a 50% increase of proliferation at 10(-5) M, and a 175% increase of intracellular lipids. On the other hand, the proliferation of facial sebocytes was significantly stimulated by testosterone with a 50%-stimulatory concentration at 10(-6) to 10(-5) M and mostly by 5 alpha-dihydrotestosterone with a 50% enhancement at 10(-8) to 10(-7) M. Spironolactone inhibited the proliferation of facial sebocytes in a dose-dependent manner with a 25%-inhibitory concentration at 10(-9) M. Simultaneous treatment of facial sebocytes with spironolactone and testosterone or 5 alpha-dihydrotestosterone resulted in decreased proliferation when compared to the growth obtained under androgens alone.(ABSTRACT TRUNCATED AT 250 WORDS)