title: [The mechanism of action of cyproterone acetate in the treatment of hirsutism].
abstract: Cyproterone acetate (CPA) in association with percutaneously offinistered estradiol has been used for the treatment of 150 hirsute patients for periods ranging from 6 months to 3 years. A spectacular clinical improvement ensued. Plasma testosterone (T) and androstenedione (A) fell from 69 +/- 24 to 33 +/- 8 and 210 +/- 103 to 119 +/- 25 ng/dl (mean +/- SD) respectively after 3 months of treatment and remained low thereafter. In contrast, T glucuronide (Tg) and 3 alpha-androstanediol (Adiol) remained high during the whole course of treatment: 37 +/- 9 and 115 +/- 43 micrograms/24 h respectively. In vitro T 5 alpha-reductase activity (5 alpha-R) in pubic skin decreased from 147 +/- 34 to 79 +/- 17 fmol/mg skin after 1 year of treatment. To elucidate the discrepancy between plasma and urinary androgens levels, T production rate (PR) and metabolic clearance rate (MCR) were measured with the constant infusion technique in 6 patients before and after 6 months of treatment. PR decreased from 988 +/- 205 to 380 +/- 140 micrograms/24 h (mean +/- SD). In contrast MCRT increased from 1275 +/- 200 to 1632 +/- 360 1/24 h; this increase in MCRT explains the striking plasma T concentration fall and the high TG and Adiol excretion relative to the decrease in PR. Antipyrine clearance rate (n = 8) increased from 36.3 +/- 5.2 to 51.5 +/- 7.4 ml/min whereas urinary/6 beta hydroxycortisol remained unchanged. In conclusion, CPA acts through several mechanisms:(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000293:Adolescent; D000328:Adult; D000726:Androgen Antagonists / Q000627:therapeutic use*; D000735:Androstenedione / Q000097:blood; D003534:Cyproterone / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D017373:Cyproterone Acetate; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006628:Hirsutism / Q000188:drug therapy*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D013739:Testosterone / Q000097:blood
chemical_list: D000726:Androgen Antagonists; D013739:Testosterone; D000735:Androstenedione; D017373:Cyproterone Acetate; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D003534:Cyproterone
vernacular_title: Mécanisme d'action de l'acétate de cyprotérone dans le traitement de l'hirsutisme.