Kendall C W, Rao A V, Janezic S A, Temkin R J, Hollenberg M J, Lea P J
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Ontario, Canada.
J Electron Microsc Tech. 1991 Jul;18(3):223-30. doi: 10.1002/jemt.1060180304.
Improvements in the design of modern scanning electron microscopes (SEM) and new methods of specimen preparation incorporating chemical removal of the cytosol and cytoskeleton, now make it possible to view cells and their organelles in three dimensions (3D) at high magnification. In this experiment, high resolution SEM (HRSEM) utilizing new methods of tissue preparation was used to study the intracellular structures of the mouse ileum. In addition, in vivo intestinal perfusion was used to further enhance cellular preservation. Using these modifications it was possible to visualize, in 3D, the fine structure of intestinal epithelial cells and intracellular organelles such as the nucleus, mitochondria, endoplasmic reticulum, and Golgi complex, as well as microvilli and cell membrane. Whole mitochondria appeared as irregularly shaped organelles which contained tubular cristae. Plate-like cristae were not observed. The brush border was found to be closely packed array of cylindrical projections. The extensive folding and structural intricacy of lateral cell membranes between absorptive cells could only be appreciated by viewing this tissue with 3D HRSEM. The use of HRSEM to study 3D ultrastructure of cells and their organelles will improve our understanding of the structure-function relationships in both the healthy and diseased gastrointestinal tract.
现代扫描电子显微镜（SEM）设计的改进以及采用化学方法去除细胞质和细胞骨架的新标本制备方法，现在使得在高放大倍数下以三维（3D）方式观察细胞及其细胞器成为可能。在本实验中，利用新的组织制备方法的高分辨率扫描电子显微镜（HRSEM）用于研究小鼠回肠的细胞内结构。此外，采用体内肠道灌注以进一步增强细胞保存。通过这些改进，可以三维可视化肠道上皮细胞和细胞内细胞器（如细胞核、线粒体、内质网和高尔基体复合体）以及微绒毛和细胞膜的精细结构。完整的线粒体呈现为含有管状嵴的不规则形状的细胞器。未观察到板状嵴。发现刷状缘是紧密排列的圆柱形突起阵列。只有通过三维高分辨率扫描电子显微镜观察该组织，才能了解吸收细胞之间侧向细胞膜的广泛折叠和结构复杂性。使用高分辨率扫描电子显微镜研究细胞及其细胞器的三维超微结构将增进我们对健康和患病胃肠道中结构 - 功能关系的理解。
