[Study on decidual and villous cells apoptosis and its control gene in medical abortion]

To study relationship of decidual and villous cells apoptosis and its control gene B-cell lymphoma/leukemia-2(bcl-2), bcl-2 associated X protein (bax) with medical abortion.

Forty four women who volunteered to terminate their pregnancy were divided into 3 group: mifepristone group (exp. 1, n = 15), mifepristone with misoprostol group (exp. II, n = 14) and control group (n = 15). The cell cycles of DNA of the decidual and villous cells stained with Propidium Iodide (PI) were analyzed and bcl-2 and bax gene protein labeled with immuno-fluorescence were detected by flow cytometry.

The percentage of decidual cells apoptosis were (14.0 +/- 3.9)%, (22.9 +/- 6.3)%, (5.3 +/- 9.3)% and of villous apoptosis were (10.9 +/- 2.8)%, (13.9 +/- 4.7)%, (4.6 +/- 3.0)% in exp. I, exp. II and control group respectively. The apoptotic percentages in decidual and villous cells of exp. I and exp. II groups were significantly higher than that of control (P < 0.01-0.001). On DNA histogram, apoptosis peaks appeared in all the groups. The decidual cell apoptosis of exp. II groups was significantly higher than that of exp. I group (P < 0.01). Both decidual apoptotic percentages of exp. I and exp. II groups were significantly higher than that of villous (P < 0.01). Decidual bcl-2/bax ratio were 1.4 +/- 0.7, 0.9 +/- 0.3, 1.4 +/- 0.7 and villous bcl-2/bax ratio were 1.0 +/- 0.4, 0.8 +/- 0.3, 1.4 +/- 0.6 in the 3 groups respectively. Both decidual and villous bcl-2/bax ratio of exp. II group was significantly lower than that of control (P < 0.05-0.01) which was in consistent with apoptosis.

These data indicated that mifepristone with misocprostol for terminating human early pregnancy might be realized by inducing decidual and villous cells excessive apoptosis. The descent of bcl-2/bax ratio could be one of the factors of inducing decidual and villous apoptosis.