title: Evidence for a primary abnormality of thecal cell steroidogenesis in the polycystic ovary syndrome.
abstract: OBJECTIVE
  Polycystic ovary syndrome (PCOS) is a common endocrinopathy of unknown aetiology. The aims of this study were to identify whether ovarian thecal cell steroidogenesis is abnormally regulated in PCOS by measuring steroid responses to a single dose of hCG before, and during, suppression of endogenous LH levels by GnRH analogue (GnRHa).
  
  
  METHODS
  Serum levels of LH, FSH, 17 alpha hydroxyprogesterone (17OHP), androstenedione, testosterone and dehydroepiandrosterone sulphate were measured before, and 48 hours after, a single intramuscular injection of 10,000 IU hCG. The test was repeated 4 weeks after suppression of endogenous LH levels by GnRHa.
  
  
  METHODS
  The ovarian responses to hCG were compared in three groups of women. Eleven women had normal ovaries and regular cycles, eight had polycystic ovaries but not clinical features of the syndrome (PCO group) and eight had polycystic ovaries, anovulation and either severe hirsutism or alopecia (PCOS group).
  
  
  RESULTS
  Before GnRHa treatment, LH levels were significantly higher in the PCOS group but hCG stimulated a similar rise in 17OHP in all three groups. Following analogue, LH levels were suppressed in all three groups but the 17OHP responses to hCG were significantly higher in both the PCO and PCOS groups compared with normal controls.
  
  
  CONCLUSIONS
  These findings provide further evidence in favour of an intrinsic abnormality of thecal cell steroidogenesis in the polycystic ovary.
authors.affiliation: Department of Obstetrics and Gynaecology, Imperial College School of Medicine at St Mary's Hospital, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Gilling-Smith
authors.forename: H
authors.initials: H
authors.lastname: Story
authors.forename: V
authors.initials: V
authors.lastname: Rogers
authors.forename: S
authors.initials: S
authors.lastname: Franks
mesh_terms: D019326:17-alpha-Hydroxyprogesterone / Q000097:blood; D000293:Adolescent; D000328:Adult; D000735:Androstenedione / Q000097:blood; D006063:Chorionic Gonadotropin; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage / Q000031:analogs & derivatives; D006065:Gonadotropins, Pituitary / Q000097:blood*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008875:Middle Aged; D011085:Polycystic Ovary Syndrome / Q000378:metabolism*; D013739:Testosterone / Q000097:blood; D013799:Theca Cells / Q000378:metabolism*
chemical_list: D006063:Chorionic Gonadotropin; D012739:Gonadal Steroid Hormones; D006065:Gonadotropins, Pituitary; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D000735:Androstenedione; D019314:Dehydroepiandrosterone Sulfate; D019326:17-alpha-Hydroxyprogesterone; D007986:Luteinizing Hormone