Tight junction of sinus endothelial cells of the rat spleen.
Tight junction of sinus endothelial cells of the rat spleen.
复制标题
大鼠脾窦内皮细胞的紧密连接。
DOI：
10.1054/tice.1999.0067
复制
发表时间：
1999
期刊：
影响因子：
2.6
通讯作者：
M. Miyoshi
中科院分区：
文献类型：
--
作者：
K. Uehara;M. Miyoshi
通过透射电子显微镜，使用冷冻断裂，Triton提取和镧示踪技术，研究了大鼠脾窦内皮细胞之间的紧密连接的精细结构和窦内皮细胞的通透性。在冷冻断裂复制品，分段股和凹槽的紧密连接经常观察到的窦内皮细胞的基底侧表面上的环纤维的位置无关。有一个或两个波浪线或凹槽，在大多数情况下，平行于细胞长轴定向，从而在某些地方形成网络。此外，一些股或凹槽是不连续的，而一些连接股的网络是不封闭的。这些股在紧密连接中偶尔也缺乏膜内颗粒。连接链在某些部位以顶基方式延伸。在硝酸镧处理的窦内皮细胞的垂直切片中，尽管在内皮细胞并置的任何地方都没有观察到紧密连接，但大多数紧密连接位于相邻内皮细胞侧面的基底部分。在相邻内皮细胞侧面的垂直切片中观察到几个连接膜的融合。除了连接膜的融合，相邻内皮细胞的细胞间隙是电子致密的，硝酸镧的渗透被发现不中断这些紧密连接。基于这些观察，分子的“栅栏”和细胞旁的“门”功能的窦内皮细胞的紧密连接进行了讨论。
The fine structure of the tight junctions between sinus endothelial cells of the rat spleen and the permeability of such sinus endothelial cells were examined by transmission electron microscopy, using freeze-fracture, triton extraction, and lanthanum-tracer techniques. In freeze-fracture replicas, the segmented strands and grooves of the tight junctions were frequently observed on the basolateral surfaces of the sinus endothelial cells irrespective of the location of the ring fiber. There were one or two wavy-strands or grooves which were, for the most part, oriented parallel to the long cell axis thus forming networks at places. In addition, some strands or grooves were discontinuous while some networks of the junctional strands were not closed. These strands also occasionally lacked intramembranous particles in the tight junctions. The junctional strands run apicobasically at certain sites. In the vertical sections of the sinus endothelial cells treated with lanthanum nitrate, although no tight junctions were observed wherever the endothelial cells were apposed, most of them were situated on the basal part of the lateral surfaces of the adjacent endothelial cells. Several fusions of the junctional membranes were observed in a vertical section of the lateral surfaces of the adjacent endothelial cells. The intercellular spaces of the adjacent endothelial cells except for the fusion of the junctional membranes, were electron dense and the infiltration of lanthanum nitrate was found not to be interrupted by these tight junctions. Based on these observations, the molecular 'fence' and paracellular 'gate' functions of the tight junctions in the sinus endothelial cells are discussed.