Schubert T, Friede R L
J Neuropathol Exp Neurol. 1981 Mar;40(2):134-54. doi: 10.1097/00005072-198103000-00006.
Counts of nuclei in electron micrographs of rat sciatic nerve show that approximately one third of the nuclear population is fibroblasts. Comparison of these figures with counts in teased fibers indicates that the majority of fibroblasts adheres tightly to myelinated nerve fibers. The early reactions and cellular transformations of the endoneurial fibroblast population upon intraneurial injections of india ink or of a purified preparation of rat sciatic myelin were studied for intervals of from 6 hours to 3 days after injection. There was phagocytosis of carbon or myelin by endoneurial fibroblasts as early as 6 hours after injection. A subsequent massive increase in phagocytic endoneurial cells appeared to develop from, and at the expense of, the normal endoneurial fibroblast population. The extent to which hematogenous monocytes also contributed to the macrophage population could not be assessed accurately by morphological criteria. Schwann cells never ingested carbon or myelin preparation during the period of investigation. Early invasion of the Schwann tube by macrophages from the endoneurial spaces could be demonstrated however. These macrophages were labeled by either carbon or myelin preparation which they had taken up from the endoneurial spaces before they entered the fibers through small gaps of the basal lamina, preferentially at the nodes of Ranvier. Carbon- or myelin-labeled hematogenous granulocytes entered nerve fibers in the same way, but the invasion of fibers by granulocytes was a transient early response limited to the first two days after injection. The data demonstrate the phagocytic capacities of endoneurial fibroblasts, their capacity for myelin degradation, and an invasion of Schwann tubes by elements of the endoneurial macrophage population during very early phases of fiber injury.
大鼠坐骨神经电子显微镜照片中的细胞核计数显示，约三分之一的细胞核群体是成纤维细胞。将这些数据与 teased 纤维中的计数进行比较表明，大多数成纤维细胞紧密附着于有髓神经纤维。研究了在神经内注射印度墨水或大鼠坐骨神经髓磷脂纯化制剂后，6 小时至 3 天内神经内膜成纤维细胞群体的早期反应和细胞转化。注射后 6 小时，神经内膜成纤维细胞就开始吞噬碳或髓磷脂。随后，吞噬性神经内膜细胞大量增加，似乎是由正常神经内膜成纤维细胞群体发展而来，并以其为代价。根据形态学标准无法准确评估血源性单核细胞对巨噬细胞群体的贡献程度。在研究期间，施万细胞从未摄取过碳或髓磷脂制剂。然而，可以证明巨噬细胞从神经内膜间隙早期侵入施万管。这些巨噬细胞被碳或髓磷脂制剂标记，它们在通过基膜的小间隙进入纤维之前，优先在郎飞结处从神经内膜间隙摄取了这些物质。碳或髓磷脂标记的血源性粒细胞以同样的方式进入神经纤维，但粒细胞对纤维的侵入是一种短暂的早期反应，仅限于注射后的前两天。这些数据证明了神经内膜成纤维细胞的吞噬能力、它们降解髓磷脂的能力，以及在纤维损伤的非常早期阶段神经内膜巨噬细胞群体的成分对施万管的侵入。
