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 after terminating early pregnancy by mifepristone plus misoprostol.

METHODS

Forty-five decidua specimens were obtained from 45 pregnant women with amenorrhea of 6-7 week duration. Fifteen women were treated with mifepristone and 15 were treated with mifepristone plus misoprostol. The remaining 15 served as controls. The tPA and PAI-1 mRNA levels were estimated by reverse transcription-polymerase chain reaction. Chromogenic assay and enzyme-linked immunosorbent assay were used to detect tPA activity and PAI-1 protein level in decidua.

RESULTS

The activities of tPA in the mifepristone plus misoprostol group and 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 mifepristone 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 +/- 0.17). 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 early decidua by post-transcription pathways, which may influence decidua shedding, endometrial angiogenesis, endometrial remodeling, and cause prolonged uterine hemorrhage after drug abortion.