Andrews P M
J Cell Biol. 1976 Mar;68(3):420-9. doi: 10.1083/jcb.68.3.420.
Scanning electron microscopy reveals that the free surfaces of stratified squamous epithelial cells lining the alimentary tract, cornea, and conjunctiva exhibit characteristic ridge-like folds of plasmalemma. These microplicae are approximately 0.1-0.2 micronm in width, of variable height (0.2-0.8 micronm) and length, may followstraight or winding paths, often branch, and exhibit a wide variety of patterns over the surfaces of cells. Transmission electron microscopy reveals that microplicae often have a fine (100-150 A) electron-dense zone subjacent to their plasmalemma and an intracellular matrix characterized by a disorderly arrary of fine filaments (40-60 A in diameter). Microplicae appear to arise from plasmalemmal fold which once provided for intercellular interdigitation and desmosome abhesion between adjacent cells. Ruthenium red staining demonstrates that microplicae and interplical grooves are covered with a polyanionic glycocalyx. Although free surface microplicae may merely represent the renmants of intercellular interdigitations or a modified expression of microvillous-like extensions, it is also possible that they serve another specific function. In this regard it is speculated that microplical and interplical grooves may function to hold a layer of lubricating and cushioning mucin designed to protect the underlying plasmalemma from abrasive abuse.
扫描电子显微镜显示，消化道、角膜和结膜内衬的复层鳞状上皮细胞的游离表面呈现出特征性的质膜脊状褶皱。这些微褶宽度约为0.1 - 0.2微米，高度（0.2 - 0.8微米）和长度可变，可能呈直线或蜿蜒路径，常分支，并在细胞表面呈现出多种模式。透射电子显微镜显示，微褶通常在其质膜下方有一个精细的（100 - 150埃）电子致密区，以及一个以细纤维（直径40 - 60埃）无序排列为特征的细胞内基质。微褶似乎起源于质膜褶皱，这种褶皱曾经用于相邻细胞之间的细胞间交错和桥粒黏附。钌红染色表明，微褶和褶间沟覆盖有聚阴离子糖萼。尽管游离表面微褶可能仅仅代表细胞间交错的残余或微绒毛样延伸的一种修饰表达，但它们也有可能发挥另一种特定功能。在这方面，有人推测微褶和褶间沟可能起到容纳一层润滑和缓冲粘蛋白的作用，旨在保护下面的质膜免受磨损。
