Evidence for non genomic action of 17β estradiol on transepithelial resistance of human fetal membranes

Background : The role of hormones in the transport mechanisms of human fetal membranes in pregnancy is unclear. Estrogens are essential hormones in pregnancy and they play an important role in the ion transport via membranes. Aim : The aim of this study was to investigate the effect of 17β-estradiol on transepithelial electrical resistance in the human amniochorion. Material and methods : Specimens of human fetal membranes were obtained. 17β-estradiol, tamoxifen and their combination were added in an Ussing chamber. Transepithelial resistance was measured before and after the addition of each solution. Results : An increase in transepithelial resistance was seen after the addition of estradiol to both sides of the membranes. The effect was rapid with a peak at the 1st min of application and dose-depended. Tamoxifen, caused a similar effect but smaller in magnitude and shorter in duration. Tamoxifen in combination with estradiol inhibited only in part the action of estradiol. Conclusions : These results suggest that estradiol induces a rapid increase of transepithelial resistance in human fetal membranes in vitro via a non-genomic pathway. It is possible those changes in transepithelial resistance play a role in the control of permeability of human amniochorion.