Investigation On The Expression Of Bax And Bcl-2 In The Throphoblast Cells Of Placenta During Late Pregnancy

Objective The apoptosis in the placenta has important affect on the development and ripe of placenta. But the relationship between the apoptosis and the onset of labor remains unknown. In this study, we detected the expression of Bax and Bcl-2 which correlated with apoptosis in throphoblast cells of placenta during different terms of late pregnancy including before onset of labor and after onset of labor. We discussed the relationship between the cellar apoptosis in placeta and the onset of labor to help to elucidate its related agents.Methods Immunohistochemistry was used to detect the expression of Bax and Bcl-2 in syncytoithrophoblastcells of 91 placenta samples including before onset of labor and after onset of labor. In each sample, 10 sights under high power were selected randomly to count the positive rates of Bcl-2 and Bax. The outcome was statistically analysed by t-tested.Results The expression of Bax and Bcl-2 in the placeta existed among preterm labor, fullterm labor and postterm labor . In after onset of labor group including preterm labor 14 cases, full-term 18 cases and post-term labor 12 cases, the Bax expression was ( 42. 98 4. 74)%, ( 43. 89 3.96) %, (44.87 3.16) % respectively; the Bcl-2 expression was (31.09 5.49)%, (34. 14 3.85)%, (20.03 3.82) % respectively. In before onset of labor group including preterm labor 16 cases, full-term 19 cases and post-term labor 12 cases, the Bax expression was ( 31.09 5.49) %, (34.14 3.85) %, (20.03 3.82) % respectively, the Bcl-2 expression was (32.11 5.08) %, (32.07 2.72) %, (19.54 2.91) % respectively.1. In the preterm groups, there was no difference between Bax and Bcl-2 expression in the placeta after the onset of labor and that in the placeta before the onset of labor. In the groups of fullterm labor and postterm labor, the Bax expression after the onset of labor was remarkably higher than that before the onset of labor. There was no difference between Bcl-2 expression in the placeta after the onset of labor and that in the placeta before the onset of labor.2. The expression of Bax in the preterm placetabefore the onset of labor was remarkably higher than that in the fullterm placeta before the onset of labor. 3. There was no difference between Bax expression in the placeta of fullterm labor and that in the placeta of post-term pregnancy. The Bcl-2 expression was lower in post-term pregnancy than that in fullterm labor. Conclusions 1. The initiation of labor was correlated with the change of Bax expression in placeta. Bcl-2 expression had no correlation with the onset of labor.2. The expression of Bax in the preterm placeta before the onset of labor was remarkably higher than that in the fullterm placeta before the onset of labor. This may be due to some pathological pregnancy factors.3. Bcl-2 may play a critical role in the aging of placenta .It may result in placental dysfunction.