Brown D
Anat Rec. 1978 May;191(1):103-10. doi: 10.1002/ar.1091910109.
The rough endoplasmic reticulum (RER) of Xenopus laevis hepatocytes was examined by freeze-fracture and by conventional thin section electron microscopy. Much of the RER was present as stacks of cisternae at the cell periphery but, in addition, large whorls of cisternae were seen in the cytoplasm in most sections. Freeze-fracture replicas revealed fenestrae in both stacked and whorled cisternae, although the fenestrae were more numerous in the whorls. The role of these fenestrae is unknown, but such structures would facilitate access of precursors to the protein synthetic machinery in this highly metabolically active cell type. This would be particularly important in RER whorls, where the innermost cisternae would otherwise be isolated from the rest of the cytoplasm.
通过冷冻蚀刻和传统超薄切片电子显微镜对非洲爪蟾肝细胞的粗面内质网（RER）进行了检查。大部分粗面内质网以细胞周边的扁平囊堆叠形式存在，但此外，在大多数切片的细胞质中还可见到大量扁平囊的涡旋结构。冷冻蚀刻复制品显示，堆叠和平行排列的扁平囊中均有窗孔，尽管平行排列的扁平囊中窗孔更多。这些窗孔的作用尚不清楚，但这样的结构将有助于前体物质进入这种高代谢活性细胞类型中的蛋白质合成机制。这在粗面内质网涡旋结构中尤为重要，否则最内层的扁平囊将与细胞质的其余部分隔离。
