Prolactin modulates peripheral androgen metabolism.
Although hyperprolactinemia may be associated with hyperandrogenism, if hirsutism develops, it is usually a mild form. This study was designed to investigate whether prolactin (PRL) modulates 5 alpha-reductase activity (5 alpha-RA), because 5 alpha-RA is known to be a major factor influencing the manifestation of androgenicity. Compared with normal women, euprolactinemic hirsute and both hyperprolactinemic hirsute and nonhirsute women had elevated levels of unbound testosterone (uT). Serum 3 alpha-androstanediol glucuronide (3 alpha-diol-G) was elevated only in patients who were hirsute, and serum 3 alpha-diol-G/uT ratios were elevated in euprolactinemic hirsute patients and normal in hyperprolactinemic hirsute patients. Genital skin 5 alpha-RA in vitro was elevated only in euprolactinemic hirsute women. The previously recognized positive correlation between 5 alpha-RA and the severity of hirsutism was dissociated with hyperprolactinemia. Human PRL incubated in vitro with normal genital skin also inhibited 5 alpha-RA. These data suggest that PRL modulates 5 alpha-RA and peripheral androgen metabolism and that other factors may also be involved in the evolution of hirsutism in hyperprolactinemia.
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000378:metabolism*; D000328:Adult; D000728:Androgens / Q000097:blood*; D015113:Androstane-3,17-diol / Q000031:analogs & derivatives / Q000097:blood; D003687:Dehydroepiandrosterone / Q000031:analogs & derivatives / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate; D013196:Dihydrotestosterone / Q000097:blood; D005260:Female; D005836:Genitalia, Female; D006628:Hirsutism / Q000097:blood* / Q000201:enzymology / Q000209:etiology; D006801:Humans; D006966:Hyperprolactinemia / Q000097:blood* / Q000150:complications / Q000201:enzymology; D066298:In Vitro Techniques; D008875:Middle Aged; D011388:Prolactin / Q000494:pharmacology / Q000502:physiology*; D012867:Skin / Q000187:drug effects / Q000201:enzymology; D013739:Testosterone / Q000097:blood
D000728:Androgens; D013196:Dihydrotestosterone; D015113:Androstane-3,17-diol; C028895:androstane-3,17-diol glucuronide; D013739:Testosterone; D003687:Dehydroepiandrosterone; D019314:Dehydroepiandrosterone Sulfate; D011388:Prolactin; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase