title: The effect of spironolactone on genital skin 5 alpha-reductase activity.
abstract: The effect of spironolactone (S) on genital skin 5 alpha-reductase activity (5 alpha-RA) of hirsute women (HW) in vivo as well as in normal genital skin in vitro was evaluated. Thirteen HW (Ferriman-Gallwey score of 23.3 +/- 2.8) received S 100 mg twice a day for a month. Twenty-three non-hirsute women were selected as controls for the assessment of genital skin 5 alpha-RA. S was added to incubations of genital skin from 9 additional controls in vitro in concentrations from 1.2 X 10(-8) to 10(-5) M. HW had significantly higher conversion ratios (CR) of T to DHT compared to controls (P less than 0.05). Post treatment values for the CR T to DHT were significantly lower than prior to S (17.5 +/- 1.7 and 8.05 +/- 1.2%, P less than 0.05) and the mass of DHT produced also decreased by 37 +/- 9% (P less than 0.05). The CR T to 3 alpha-diol decreased by 30 +/- 9% (P less than 0.05). In 11 of 13 women, a significant reduction of 5 alpha-RA was demonstrated while in 2 patients the activity remained unchanged. The maximum in vitro inhibitory effect of S on the CR T to DHT occurred with a concentration of 1.2 X 10(-5) M (P less than 0.01). In conclusion, S has a direct inhibitory effect on 5 alpha-RA. The beneficial effect of S treatment in HW may be related, in part, to this inhibition of 5 alpha-RA.
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000378:metabolism*; D000328:Adult; D005260:Female; D006628:Hirsutism / Q000201:enzymology*; D006801:Humans; D007700:Kinetics; D010088:Oxidoreductases / Q000378:metabolism*; D011085:Polycystic Ovary Syndrome / Q000201:enzymology; D012016:Reference Values; D012867:Skin / Q000201:enzymology*; D013148:Spironolactone / Q000494:pharmacology* / Q000627:therapeutic use; D014621:Vagina
chemical_list: D013148:Spironolactone; D010088:Oxidoreductases; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase