Trout J J, Buckwalter J A, Moore K C, Landas S K
Tissue Cell. 1982;14(2):359-69. doi: 10.1016/0040-8166(82)90033-7.
We examined nucleus pulposus notochordal cells of individuals ranging in age from the eighth week of fetal life to 32 years of age. With increasing age, notochordal cell structure changed, as did the cell-to-cell relationships and the cell-to-chordal relationships. All notochordal cells contained normal organelles, including well-developed endoplasmic reticulum, but, in addition, fetal notochordal cells demonstrated an unusual relationship between rough endoplasmic reticulum and mitochondria: elements of the rough endoplasmic reticulum encircled almost every mitochondrion. Fetal notochordal cells contained large amounts of glycogen, while older cells had much smaller glycogen deposits. Cytoplasmic filaments were observed in cells of all ages. The cells formed tightly packed clusters in the fetus with little, if any, extracellular matrix between individual cells. Cells separated from each other with age and by the twenty-first week of fetal life, only slender strands of cytoplasm connected them. Previous light microscopic studies described notochordal cells as 'physaliphorus' cells since they appeared to contain large cytoplasmic vacuoles. However, electron microscopy showed that these apparent vacuoles consist of extracellular matrix surrounded by cells or cell processes. The structure of notochordal cells and their persistence in the nucleus pulposus after fetal life suggest that they may have a significant role in the formation and maintenance of the nucleus pulposus.
我们研究了从胎儿期第8周到32岁个体的髓核脊索细胞。随着年龄的增长，脊索细胞的结构发生了变化，细胞间关系和细胞与脊索的关系也发生了变化。所有脊索细胞都含有正常的细胞器，包括发育良好的内质网，但此外，胎儿脊索细胞的粗面内质网和线粒体之间呈现出一种不同寻常的关系：粗面内质网的成分几乎环绕着每个线粒体。胎儿脊索细胞含有大量糖原，而年龄较大的细胞糖原沉积量则少得多。在所有年龄段的细胞中都观察到了细胞质细丝。在胎儿期，细胞形成紧密堆积的簇，单个细胞之间几乎没有细胞外基质。随着年龄增长以及到胎儿期第21周时，细胞彼此分离，只有细长的细胞质丝将它们连接起来。先前的光学显微镜研究将脊索细胞描述为“泡状细胞”，因为它们似乎含有大的细胞质空泡。然而，电子显微镜显示这些明显的空泡由被细胞或细胞突起包围的细胞外基质组成。脊索细胞的结构及其在胎儿期后在髓核中的持续存在表明它们可能在髓核的形成和维持中起重要作用。
