McGuffee L J, Little S A
Department of Pharmacology, School of Medicine, University of New Mexico, Albuquerque 87131-5316.
Scanning Microsc. 1992 Sep;6(3):837-45.
We have previously shown that dense bodies are not the static planar simple ovoidal structures they appear to be in thin sections. In this report, we present three-dimensional reconstructions from consecutive serial thin sections through shortened and non-shortened large mesenteric artery cells. Profiles of the cell surface, membrane dense bodies, and cytoplasmic dense bodies were reconstructed from consecutive thin sections and the distribution, size, shape, and spatial relationships among these components was examined. Within the cell, membrane dense bodies are numerous and occupy approximately 10% of the cell volume. Membrane dense bodies can attach to the cell surface laterally, obliquely or normally. An individual membrane dense body can be continuous over more than 2 microns of cell depth and can change shape throughout its depth. On cell shortening, many membrane dense bodies assume a crenated shape. Compared to membrane dense bodies, cytoplasmic dense bodies are smaller in all dimensions and occupy about 2% of the cell volume. In shortened cells, cytoplasmic dense bodies appear to cluster into groups. This redistribution of cytoplasmic dense bodies may be related to the reorganization of contractile units when the cell shortens.
我们之前已经表明，致密体并非如在薄切片中看似的那样是静态的平面简单卵形结构。在本报告中，我们展示了通过缩短和未缩短的大肠系膜动脉细胞的连续系列薄切片进行的三维重建。从连续薄切片重建细胞表面、膜致密体和细胞质致密体的轮廓，并检查这些组分之间的分布、大小、形状和空间关系。在细胞内，膜致密体数量众多，约占细胞体积的10%。膜致密体可横向、倾斜或垂直附着于细胞表面。单个膜致密体在超过2微米的细胞深度上可以是连续的，并且在其整个深度上可以改变形状。在细胞缩短时，许多膜致密体呈现出锯齿状。与膜致密体相比，细胞质致密体在所有维度上都较小，约占细胞体积的2%。在缩短的细胞中，细胞质致密体似乎聚集成团。细胞质致密体的这种重新分布可能与细胞缩短时收缩单位的重组有关。
