title: Effect of prolactin on follicle-stimulating hormone receptor binding and progesterone production in cultured porcine granulosa cells.
abstract: OBJECTIVE
  To determine the effect of prolactin (PRL) on follicle-stimulating hormone receptor (FSH-R) binding and progesterone (P) production in cultured porcine granulosa cells.
  
  
  METHODS
  Controlled experiment.
  
  
  METHODS
  Academic research laboratory.
  
  
  METHODS
  Immature granulosa cells were cultured in a serum-free medium. All cell populations were supplemented with porcine (p) FSH and cultured in the absence or presence of ovine (o) PRL.
  
  
  METHODS
  Specific pFSH-R binding and P in medium.
  
  
  RESULTS
  In the control cells, FSH-R binding increased 31-fold and P production increased 700-fold by day 4. Physiologic levels of oPRL potentiated the action of pFSH and resulted in a further 50% increase in pFSH-R binding and P production by day 4 over that in controls. In contrast, higher concentrations of oPRL blocked the rise in both pFSH-R binding and P production. The alteration in pFSH-R binding was associated with a change in FSH-R number.
  
  
  CONCLUSIONS
  Physiologic levels of PRL amplify the stimulatory effects of FSH on the acquisition of the FSH-R and P production in cultured granulosa cells. Higher concentrations of PRL cause a decrease in FSH-R binding and P production. Prolactin may act as a "co-gonadotropin" and fine-tune the process of folliculogenesis by altering the acquisition of granulosa FSH receptors.
authors.affiliation: University of Vermont College of Medicine, Burlington, USA. Misty.B.Porter@Hitchcock.ORG
authors.forename: M B
authors.initials: MB
authors.lastname: Porter
authors.forename: J R
authors.initials: JR
authors.lastname: Brumsted
authors.forename: C K
authors.initials: CK
authors.lastname: Sites
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004357:Drug Synergism; D004958:Estradiol / Q000096:biosynthesis; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism / Q000494:pharmacology; D006107:Granulosa Cells / Q000187:drug effects* / Q000378:metabolism*; D007457:Iodine Radioisotopes; D011374:Progesterone / Q000096:biosynthesis*; D011388:Prolactin / Q000494:pharmacology*; D011962:Receptors, FSH / Q000378:metabolism*; D012756:Sheep; D013552:Swine
chemical_list: D007457:Iodine Radioisotopes; D011962:Receptors, FSH; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; D005640:Follicle Stimulating Hormone