title: Role of Insulin-like growth factors in initiation of follicle growth in normal and polycystic human ovaries.
abstract: BACKGROUND
  Polycystic ovary syndrome (PCOS), the commonest cause of anovulatory infertility, is characterized by disordered follicle development including increased activation and accelerated growth of preantral follicles. Data from experimental animals and preliminary results from studies of human ovarian tissue suggest that IGFs affect preantral follicle development.
  
  
  OBJECTIVE
  Our objectives were to investigate the expression of the type-1 IGF receptor (IGFR-1) in the human ovary and to determine whether IGFs are involved in stimulating the transition of follicles from primordial to primary stage in normal and polycystic ovaries.
  
  
  METHODS
  We used archived ovarian tissue for protein expression studies and small cortical biopsies for follicle isolation and for tissue culture.
  
  
  METHODS
  This was a laboratory-based study, using clinical tissue samples.
  
  
  METHODS
  A total of 54 women, 33 with normal ovaries and 21 with polycystic ovaries, were classified by reference to menstrual cycle history and ultrasonography.
  
  
  METHODS
  We evaluated expression of IGFR-1 mRNA in isolated preantral follicles and of IGFR-1 protein in archived ovarian tissue samples from normal and polycystic ovaries and effects of exogenous IGF-1 on preantral follicle development and survival in cultured fragments of normal and polycystic ovaries.
  
  
  RESULTS
  IGFR-1 mRNA and protein was expressed in preantral follicles at all stages of development and enhanced expression was noted in PCOS follicles during early preantral development. IGF-1 stimulated initiation of follicle growth in normal tissue but had little effect on preantral follicle growth in polycystic ovaries in which, characteristically, there was a higher proportion of follicles that had entered the growing phase even before culture.
  
  
  CONCLUSIONS
  IGFs are plausible candidates in regulation of initiation of human follicle growth, and accelerated preantral follicle growth in PCOS may be due to increased activity of endogenous IGFs.
authors.affiliation: Institute of Reproductive and Developmental Biology, Wolfson and Weston Research Centre for Family Health, Imperial College London, London, W12 0NN, United Kingdom.
authors.forename: Sharron A
authors.initials: SA
authors.lastname: Stubbs
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Webber
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Stark
authors.forename: Suman
authors.initials: S
authors.lastname: Rice
authors.forename: Raul
authors.initials: R
authors.lastname: Margara
authors.forename: Stuart
authors.initials: S
authors.lastname: Lavery
authors.forename: Geoffrey H
authors.initials: GH
authors.lastname: Trew
authors.forename: Kate
authors.initials: K
authors.lastname: Hardy
authors.forename: Stephen
authors.initials: S
authors.lastname: Franks
mesh_terms: D000328:Adult; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D008875:Middle Aged; D006080:Ovarian Follicle / Q000187:drug effects / Q000254:growth & development*; D011085:Polycystic Ovary Syndrome / Q000503:physiopathology*; D012333:RNA, Messenger / Q000032:analysis; D017526:Receptor, IGF Type 1 / Q000032:analysis / Q000235:genetics; D013002:Somatomedins / Q000502:physiology*
chemical_list: D012333:RNA, Messenger; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1