Enders A C, Liu I K
Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis 95616.
Am J Anat. 1991 Dec;192(4):366-81. doi: 10.1002/aja.1001920405.
The structure of the equine chorionic girdle between days 28 and 42 of gestation was examined. Of particular interest were differentiation of trophoblastic cells within the girdle, adhesion between girdle and endometrium, invasion and displacement of the uterine epithelium, and the nature of the endometrium when girdle cells migrate into it to form endometrial cup cells. The chorionic girdle, identified initially as a band of tall columnar cells, becomes a stratified columnar epithelium indented by clefts and pits. Adhesion to and penetration through the endometrial luminal epithelium are rapid and occur initially in very limited areas. Stromal invasion occurs as strands of contiguous trophoblast cells invade through the basal lamina. Only girdle cells that are adjacent to the basal lamina or have entered the endometrial stroma undergo hypertrophy and differentiate into cup cells. At the initiation of trophoblastic invasion, the luminal epithelium contains numerous, large, intraepithelial, granular lymphocytes; small lymphocytes then accumulate in the stroma, but by day 42 lymphocytes are largely confined to the periphery of the cup. Although adhesion of trophoblast to the endometrial surface is initiated by small groups of girdle cells on restricted areas of the endometrial folds, the area is then increased by new areas of adhesion and by expansion of the initial invasion. Areas of girdle cells that do not attach undergo necrosis, as do superficial portions of areas of invasion. Consequently the girdle cells that form cups may be a minority of the original population. It is suggested that the differentiation of girdle cells is closely programmed and that cells that do not reach the stroma become necrotic at the same time that endometrial cup cells are differentiating.
对妊娠28至42天之间马的绒毛带结构进行了检查。特别令人感兴趣的是绒毛带内滋养层细胞的分化、绒毛带与子宫内膜之间的黏附、子宫上皮的侵袭和移位，以及当绒毛带细胞迁移到子宫内膜中形成子宫内膜杯状细胞时子宫内膜的性质。绒毛带最初被识别为一条高柱状细胞带，随后变成由裂隙和凹坑凹陷的复层柱状上皮。与子宫内膜腔上皮的黏附和穿透迅速发生，最初发生在非常有限的区域。间质侵袭表现为连续的滋养层细胞条索穿过基膜。只有与基膜相邻或已进入子宫内膜间质的绒毛带细胞会发生肥大并分化为杯状细胞。在滋养层侵袭开始时，腔上皮含有大量大的上皮内颗粒淋巴细胞；小淋巴细胞随后在间质中积聚，但到第42天时，淋巴细胞主要局限于杯状细胞的周边。尽管滋养层与子宫内膜表面的黏附由子宫内膜皱襞受限区域上的一小群绒毛带细胞启动，但随后该区域会因新的黏附区域和初始侵袭的扩展而增加。未附着的绒毛带细胞区域会发生坏死，侵袭区域的表层部分也会如此。因此，形成杯状细胞的绒毛带细胞可能只是原始群体中的少数。有人提出，绒毛带细胞的分化是紧密编程的，未到达间质的细胞在子宫内膜杯状细胞分化的同时会发生坏死。
