人胎盘滋养层细胞的超微结构及凋亡

The Ultrastructures and Apoptosis of Human Trophoblast

目的 :观察不同孕期胎盘滋养层细胞的超微结构和凋亡现象。方法 :取早、中、晚各期胎盘组织 ,制备成透射电镜标本并观察。结果 :细胞滋养层细胞 (CT)在各妊娠时期形态结构相似 ,呈低分化细胞的特点。细胞核常染色质丰富 ,细胞质中有大量散在游离核糖体 ,内质网较少 ,高尔基复合体不发达。合体滋养层细胞 (ST)为分化良好的细胞。细胞质内含丰富的扩张内质网 ,高尔基复合体发达。CT核数 /ST核数随妊娠时间增加而减少。中、晚期有些ST核染色质呈边集、固缩等凋亡表现 ,且多发生在合体结 ,足月胎盘ST的凋亡指数AI大于中期 (P <0 .0 1)。结论

Objective:To study the ultrastructures and apoptosis of human trophoblasts in different gestational periods. Methods:Specimens from the placentae of first, second and third trimesters of pregnancy were prepared and observed under electronic microscope. Results:The cytotrophoblast (CT) had many characteristics such as plenty of euchromtin, abundant sparse ribosomes and rare endoplasmic reticulum and Golgi complex, which indicated the low degree differentiation of the cells. There was no significant difference in CT of different gestational periods. The syncytiotrophoblasts (ST) were well differentiated. They had prosperous enlarged endoplasmic reticulum and Gogi complex in their cytoplasma. The ratio of the nucleus of CT to ST was decreased during the gestational periods. The condensed chromatin of ST in placentas of second and third trimester which occurred more frequently in synknots implied that apoptosis had come off. The Apoptosis Index (AI) of ST in third trimester was more than that in the second trimester ( P<0.01 ). Conclusion:The morphological change of trophoblasts was related to the apoptosis of ST.