Abstract:

To investigate the effect of mifepristone on the  function of transforming growth factor β signal transduction in chorionic villi and the molecular mechanism of mifepristone inducing abortion. MethodsEarly pregnant chorionic villi were obtained from the surgical aspiration group(n=13) and the mifepristone inducing abortion group(n=20). Expression of smad7 which was the targeting gene of  the TGFβ/smads signal transduction pathway in chorionic villi was determined by  immunohistochemical staining  with specific antibody and RTPCR. Mean optic density and density scale were anzlyzed. ResultsMean optic density of Smad7  in chorionic villi in the mifepristone inducing abortion  group(0.346?6±0.046?9) was statistically higher than that in the surgical aspiration group(0.233?7±0.065?7)(P<0.01). Also, density scale of smad7mRNA in chorionic  villi in the mifepristone inducing abortion group(0.561?7±0.410?3) was  statistically higher than that in the surgical aspiration   group(0.222?2±0.244?1)(P<0.02). ConclusionMifepristone can upregulate  the function of  the TGFβ/smads signal  transduction pathway and expression of  targeted genes, such as plasminogen  activator inhibitor 1, affect migration and  evasion of tropholast  cells, which may be one of the  molecular mechanisms for termination of early  pregnancy by this drug.

Key words: Mifepristone; Chorion; Transforming growth factorβ;  Plasminogen activator inhibitor