Doty S B
Calcif Tissue Int. 1981;33(5):509-12. doi: 10.1007/BF02409482.
Cell membrane specializations occur at contact sites between adjacent osteoblasts and osteoblasts and osteocytes. These junctions have been described by other investigators as being important in preventing the extracellular movement of material around bone cells. Previously we described how certain small proteins circumvented the osteoblast population and rapidly penetrated the canalicular-osteocyte system. In the present study we used lanthanum colloid as an extracellular marker, the lanthanum readily penetrated the bone cell junctions and the extracellular space of bone. Morphologically, these junctions were not "tight" or "occluding" structures, but resembled "gap" junctions. These gap junctions contained elements which formed intercellular bridges between adjacent cells but also maintained a 2 nm space between cells that contained extracellular fluid. These gap junctions may have an important function in the control or coordination of bone cell activity throughout a given volume of bone.
细胞膜特化出现在相邻成骨细胞之间以及成骨细胞与骨细胞的接触部位。其他研究者已描述这些连接对于防止物质在骨细胞周围进行细胞外移动很重要。此前我们描述了某些小蛋白如何绕过成骨细胞群体并迅速穿透骨小管 - 骨细胞系统。在本研究中，我们使用镧胶体作为细胞外标记物，镧很容易穿透骨细胞连接以及骨的细胞外间隙。从形态学上看，这些连接并非“紧密”或“封闭”结构，而是类似于“缝隙”连接。这些缝隙连接包含在相邻细胞之间形成细胞间桥的成分，但在含有细胞外液的细胞之间也保留了2纳米的空间。这些缝隙连接可能在控制或协调给定体积骨内的骨细胞活动方面具有重要功能。
