小鼠囊胚在子宫内膜体外共培养模型上着床的超微结构观察

目的:进一步证明已建立的体外着床模型的可行性。方法:将妊娠d4的小鼠囊胚培养在已建立的体外子宫内膜共培养模型上,电镜观察胚胎植入时囊胚与子宫内膜上皮细胞相互关系的超微结构。结果:小鼠囊胚能正常脱透明带、黏附和扩展。扫描电镜见黏附在子宫内膜上的囊胚呈椭圆形或扁平形;胚胎表面具微绒毛;在胚胎与子宫内膜细胞接触点可见胚胎滋养细胞黏附于胞饮突上。透射电镜观察显示,胚胎滋养细胞通过微绒毛黏附于上皮细胞上,有些滋养细胞通过微绒毛开始植入,局部滋养细胞与上皮细胞形成紧密连接。胚胎滋养细胞与上皮细胞间形成许多镶嵌连接。超微结构显示粗面内质网、线粒体、溶酶体和核糖体非常丰富。结论:小鼠囊胚在子宫内膜体外模型上生长发育良好,该胚胎与子宫内膜共培养系统是研究胚胎着床机理的理想体外模型。

Ultrastructural Study on Implantation of Mouse Blastocysts on an in vitro Three-dimensional Endometrium

Objective: To establish an ideal implantation model. Methods: The mice blastocysts on day 4 of pregnancy were cultured on a three-dimensional endometrium in vitro. The implantation site obtained in vitro were investigated by electron microscope. Results: It showed that the shedding zona pellucide development, attachment and outgrowth of blastocysts were normal. Scanning electron microscopy revealed a confluent epithelium with pinopodes, and an adhesion between the blastocysts and pinopodes presenting cells. Transmission electron micros- copy indicated a polarized columnar epithelium with an abundance of microvilli, tight junctions and intracellular glycogen deposits. The trophoblastic cell contactedto epithelial cells andthe first sign penetration was also observed. Conclusion: The cultured three-dimensional endometrium could be used as an ideal in vitro model for embryo implantation.