对正常人胎盘绒毛冷冻复型电镜研究

AN ELECTRON MICROSCOPIC STUDY OF NORMAL HUMAN PLACENTAL VILLI BY THE FREEZE-ETCHING METHOD

本文应用冷冻复型电境技术对22例由40天到足月胎儿胎盘绒毛的超微结构进行了研究,发现妊娠早期合体细胞层较厚,游离面有大量细长微绒毛,胞质内含丰富管泡,随妊娠进行,微绒毛逐渐减少变短,末端扩张,胞质内大泡逐渐增多。细胞核孔随胎龄增长而增多。在合体细胞近游离端还发现有紧密连接和不完全分隔合体细胞的膜。细胞滋养层细胞早期成层,以后逐渐减少,细胞外形规则,细胞器少,核孔变化与合体细胞者基本相同,细胞间及与合体细胞间可见桥粒与缝管连接。在二层细胞间我们观察到由细胞滋养层向合体细胞过渡分化的细胞。对上述结果的意义进行了讨论。

22 cases of placental villi obtained from 40 days of gestation to full term were studied by means of freeze-etching technique. In early stage of pregnance, the syncytial layer was thicker, the free surface of syncytium exhibited many microvilli which were thin and long. The cytoplasma contained abundant vesicles. The microvilli became shorter and fewer with prolongation of pregnancy and it's end enlarged, and cytoplasma became more visicular. Neuclear pores were increased with the age of pregnancy. Tight junction and cell membrance which seperated syncytium incompletely near apical part of syncytium were revealed. Cytotrophoblast was a layer in early stage, later on, it became fewer and fewer. Between cytotrophoblasts and syncytium desmosomes and gap junction were seen. Intermediate ceils differentiated from cytotrophoblast which would contribute to the syncytium were demonstrated. The resultes were discussed with references,