Tissue-type plasminogen activator and plasminogen activator inhibitor type-1 mRNA and their protein expression levels in human decidua after early pregnancy termination by mifepristone plus misoprostol

Objective To investigate the mechanism of prolonged uterine hemorrhage afte r terminating early pregnancy by mifepristone plus misoprostol. Methods Forty-five decidua specimens were obtained from 45 pregnant women w ith amenorrhea of 6-7 week duration. Fifteen women were treated with mifepr istone and 15 were treated with mifepristone plus misoprostol. The remainin g 15 served as controls. The tPA and PAI-1 mRNA levels were estimated by re verse transcription-polymerase chain reaction. Chromogenic assay and enzyme -linked immunosorbent assay were used to detect tPA activity and PAI-1 prot ein level in decidua. Results The activities of tPA in the mifepristone plus misoprostol group an d in the mifepristone group were 46.91 +/- 20.74 IU/mg protein and 64.25 +/ - 35.81 IU/mg protein respectively, lower than those in the normal decidua group (99.76 +/- 58.61 IU/mg protein, P < 0.05). tPA mRNA levels in the mif epristone plus misoprostol group were the highest (1.43 +/- 0.39) among the groups. In the mifepristone group, tPA mRNA level (0.90 +/- 0.16) was not significantly different from that in the normal decidua group (0.94 +/- 0.1 7). The protein and mRNA expression levels of PAI-1 were not significantly different among the three groups (P > 0.05). Conclusions Mifepristone plus misoprostol decreased tPA activity in human e arly decidua by post-transcription pathways, which may influence decidua sh edding, endometrial angiogenesis, endometrial remodeling, and cause prolong ed uterine hemorrhage after drug abortion.