Blankenship T N, Given R L
Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, USA.
Anat Rec. 1995 Sep;243(1):27-36. doi: 10.1002/ar.1092430105.
Removal of the uterine luminal epithelium and its basement membrane is necessary for successful implantation of invasive blastocysts. Few reports, however, have specifically addressed the penetration and loss of the uterine luminal epithelial basement membrane (UEBM). We investigated the loss of UEBM by examining the distribution of laminin and type IV collagen.
Blastocyst implantation sites were collected from mice on days 5, 6, and 7 of pregnancy. Paraffin sections were prepared from these tissues and processed with standard immunoperoxidase techniques to reveal the distribution of laminin and type IV collagen.
On day 5 of pregnancy blastocysts were adherent to the uterine epithelium. The epithelium and UEBM were complete and uninterrupted. On day 6 the juxtaembryonic uterine epithelium was lost and focal discontinuities were seen along the UEBM. By 1200 hr the UEBM had receded to the region near the ectoplacental cone, but staining was reduced for both antigens over the entire region surrounded by decidual cells. This decreased staining of the UEBM occurred in areas not yet occupied by trophoblast cells. On day 7 the UEBM was lost over the entire embryonic half of the uterine lining, corresponding to the distribution of decidual cells.
Progressive loss of the UEBM occurred in a consistent spatiotemporal pattern following the onset of blastocyst implantation. Diminished immunoreactivity of laminin and type IV collagen in the UEBM was closely correlated with the area occupied by decidualized endometrial stroma and occurred in areas not yet in contact with trophoblast cells. We conclude that decidual cells are instrumental in the removal of UEBM during early pregnancy.
侵袭性囊胚成功着床需要去除子宫腔上皮及其基底膜。然而，很少有报告专门探讨子宫腔上皮基底膜（UEBM）的穿透和丧失情况。我们通过检测层粘连蛋白和IV型胶原的分布来研究UEBM的丧失。
在妊娠第5、6和7天从小鼠收集囊胚着床部位。从这些组织制备石蜡切片，并用标准免疫过氧化物酶技术处理以显示层粘连蛋白和IV型胶原的分布。
妊娠第5天，囊胚附着于子宫上皮。上皮和UEBM完整且连续。第6天，胚胎旁的子宫上皮消失，沿UEBM可见局灶性中断。到1200小时，UEBM已退缩到外胎盘锥附近区域，但在蜕膜细胞包围的整个区域，两种抗原的染色均减少。UEBM的这种染色减少发生在尚未被滋养层细胞占据的区域。第7天，UEBM在子宫 lining胚胎侧的整个区域消失，与蜕膜细胞的分布相对应。
囊胚着床开始后，UEBM以一致的时空模式逐渐丧失。UEBM中层粘连蛋白和IV型胶原免疫反应性降低与蜕膜化子宫内膜基质占据的区域密切相关，且发生在尚未与滋养层细胞接触的区域。我们得出结论，蜕膜细胞在妊娠早期去除UEBM中起作用。
