Parr M B, Parr E L
J Reprod Fertil. 1982 Nov;66(2):739-44. doi: 10.1530/jrf.0.0660739.
The luminal surfaces of non-ciliated uterine epithelial cells of 17 rabbits on Days 4--6 of pregnancy were studied histologically with light microscopy, transmission and scanning electron microscopy. The luminal surfaces of most epithelial cells exhibited short microvilli and did not project into the uterine lumen. However, the surfaces of some cells showed fewer microvilli and bulged out into the uterine lumen, giving the cells a dome-like appearance. The domes appeared most frequently on Day 6 of pregnancy and contained a few ribosomes, mitochondria, and membranous elements; large vacuoles and granules were absent. The domes were not involved in endocytosis. Ferritin introduced into the uterine lumen was incorporated into the cells by coated micropinocytotic invaginations at the base of the microvilli, rather than by any activity of the domes. There was also no indication that the domes pinched off to produce an apocrine secretion. The size and frequency of domes were, however, clearly related to the fixation procedure. Epithelial cells from uteri fixed by vascular perfusion showed fewer and less prominent domes, while cells from uteri fixed by immersion displayed a larger number of domes that projected further into the uterine lumen. The domes in the rabbit epithelium therefore differ structurally and functionally from the apical projections (pinopods) that occur in the uterine epithelium of the rat and mouse during the peri-implantation period.
用光学显微镜、透射电子显微镜和扫描电子显微镜对17只处于妊娠第4 - 6天的家兔非纤毛子宫上皮细胞的腔面进行了组织学研究。大多数上皮细胞的腔面有短微绒毛，不向子宫腔内突出。然而，一些细胞的表面微绒毛较少，向子宫腔内突出，使细胞呈现圆顶状外观。圆顶在妊娠第6天出现得最为频繁，含有一些核糖体、线粒体和膜性成分；没有大的液泡和颗粒。圆顶不参与胞吞作用。引入子宫腔的铁蛋白是通过微绒毛基部的有被微胞饮内陷进入细胞的，而不是通过圆顶的任何活动。也没有迹象表明圆顶会脱离以产生顶浆分泌。然而，圆顶的大小和频率显然与固定程序有关。通过血管灌注固定的子宫上皮细胞显示出较少且不太明显的圆顶，而通过浸入固定的子宫上皮细胞显示出更多的圆顶，且这些圆顶向子宫腔内突出得更远。因此，家兔上皮中的圆顶在结构和功能上与大鼠和小鼠植入前期子宫上皮中出现的顶端突起（微绒毛）不同。
