title: Administration of an antiprogesterone up-regulates estrogen receptors in the endometrium of women using Norplant: a pilot study.
abstract: OBJECTIVE
  To determine the effect of a single dose of mifepristone (200 mg) on endometrial estrogen and progesterone receptors in Norplant users.
  
  
  METHODS
  A prospective single-blind placebo-controlled pilot study. SETTING; Women were recruited from a large family planning clinic and were studied either at the clinic or in a clinical research unit attached to a teaching hospital gynecology department.
  
  
  METHODS
  Eight women using Norplant and experiencing vaginal bleeding more often than once every 24 days. All completed the study.
  
  
  METHODS
  Endometrial biopsies were taken after treatment with both placebo and 200 mg of mifepristone, both given at the start of a bleeding episode.
  
  
  METHODS
  Expression of endometrial progesterone (PR) and estrogen (ER) receptors, ovulation, and vaginal bleeding.
  
  
  RESULTS
  Mifepristone administration was associated with down-regulation of PR receptor subtype B and up-regulation of ER. Women treated with mifepristone showed a tendency to increased ovulation rates and reduced vaginal bleeding.
  
  
  CONCLUSIONS
  The effect of mifepristone on endometrial steroid receptors was consistent with functional inhibition of progesterone. The findings warrant further investigation of this regimen as a strategy to reduce frequent bleeding.
authors.affiliation: Department of Obstetrics and Gynaecology, Centre for Reproductive Biology, University of Edinburgh, 37 Chalmers Street, Edinburgh, EH9 3ET, Scotland, UK. a.glasier@ed.ac.uk
authors.forename: Anna F
authors.initials: AF
authors.lastname: Glasier
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Jane E
authors.initials: JE
authors.lastname: Davie
authors.forename: R W
authors.initials: RW
authors.lastname: Kelly
authors.forename: Hilary O D
authors.initials: HO
authors.lastname: Critchley
mesh_terms: D001706:Biopsy; D003280:Contraceptives, Oral, Synthetic / Q000009:adverse effects / Q000494:pharmacology*; D004347:Drug Interactions; D004717:Endometrium / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D006727:Hormone Antagonists / Q000009:adverse effects / Q000494:pharmacology*; D006801:Humans; D007150:Immunohistochemistry; D016912:Levonorgestrel / Q000009:adverse effects / Q000494:pharmacology*; D015735:Mifepristone / Q000009:adverse effects / Q000494:pharmacology*; D010865:Pilot Projects; D011374:Progesterone / Q000037:antagonists & inhibitors*; D011446:Prospective Studies; D011960:Receptors, Estrogen / Q000096:biosynthesis* / Q000235:genetics; D011980:Receptors, Progesterone / Q000096:biosynthesis; D016037:Single-Blind Method; D018709:Statistics, Nonparametric; D015854:Up-Regulation / Q000187:drug effects; D014592:Uterine Hemorrhage / Q000139:chemically induced / Q000517:prevention & control
chemical_list: D003280:Contraceptives, Oral, Synthetic; D006727:Hormone Antagonists; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C101118:progesterone receptor A; C097314:progesterone receptor B; D015735:Mifepristone; D011374:Progesterone; D016912:Levonorgestrel