Administration of an antiprogesterone up-regulates estrogen receptors in the endometrium of women using Norplant: a pilot study.
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.
Glasier
Anna F
AF
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
Wang
Hong
H
Davie
Jane E
JE
Kelly
R W
RW
Critchley
Hilary O D
HO
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
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