Raine C S, Röytta M, Dolich M
Department of Pathology (Neuropathology), Albert Einstein College of Medicine, Bronx, NY 10461.
J Neurocytol. 1987 Aug;16(4):461-8. doi: 10.1007/BF01668500.
Ultrastructural examination of regenerating axons within rat sciatic nerve injected locally with the microtubule assembly-promoting compound, taxol, has revealed the frequent association of microtubules with axoplasmic organelles, in particular mitochondria. This was characterized by the prodigious accumulation of axonal microtubules, some of which became aligned to form multilayered channels within which axoplasmic organelles were sequestered. Between each layer of microtubules forming the walls of these channels, a 5 nm filament, believed to derive from microtubule side-arm material, was present. The findings suggest that these microtubule channels might play a role in mitochondrial traffic across the lesion area. Similar but much less elaborate associations within axons between microtubules and axoplasmic organelles, including mitochondria, have been described previously. Within regenerating axonal sprouts, intermediate filaments were found only at later timepoints when they commonly occurred within the microtubule channels. It is proposed that taxol impedes axonal regrowth at an early stage of cytoskeleton formation and that that the present observations represent drug-induced exaggerations of a normal phenomenon.
对局部注射微管组装促进化合物紫杉醇的大鼠坐骨神经内再生轴突进行的超微结构检查显示，微管与轴浆细胞器，特别是线粒体频繁相关。其特征是轴突微管大量积累，其中一些微管排列形成多层通道，轴浆细胞器被隔离在这些通道内。在形成这些通道壁的每层微管之间，存在一种5纳米的细丝，据信它源自微管侧臂物质。这些发现表明，这些微管通道可能在损伤区域的线粒体运输中发挥作用。先前已经描述过轴突内微管与包括线粒体在内的轴浆细胞器之间存在类似但不太复杂的关联。在再生轴突芽中，中间丝仅在较晚的时间点出现，此时它们通常出现在微管通道内。有人提出，紫杉醇在细胞骨架形成的早期阶段会阻碍轴突再生，并且目前的观察结果代表了药物诱导的正常现象的夸张表现。
