Park-Matsumoto Y C, Kameda N, Kobayashi T, Tsukagoshi H
Department of Neurology, School of Medicine, Tokyo Medical and Dental University, Japan.
Brain Res. 1991 Nov 29;565(2):280-9. doi: 10.1016/0006-8993(91)91660-s.
So far there have been no developmental studies including the influences of innervation and contractile activity on the expression of dystrophin in cultured human muscle. We performed immunocytochemical studies of the localization of dystrophin on aneurally cultured non-contracting (AMs) and innervated continuously contracting cross-striated human muscle fibers (ICMs) with fetal rat spinal cord from normal and Duchenne muscular dystrophy (DMD) biopsied muscles. In normal AMs, myoblasts and some immature AMs showed negative staining of dystrophin, but many AMs had a patchy (discontinuous) distribution of dystrophin in the subplasmalemmal region and with some granularity near the sarcolemma and in the deeper cytoplasm. In normal ICMs, dystrophin was localized continuously at the inner aspect of the sarcolemmal membrane and some periodic dense patterns were detected in some areas. Both AMs and ICMs from DMD had negative staining of dystrophin. To investigate the muscle contractile activity on the distribution of dystrophin, we paralyzed ICMs with tetrodotoxin (TTX) for two weeks from the first appearance of muscle contractions. In paralyzed innervated muscles (PIMs), dystrophin remained in a patchy (discontinuous) pattern at the inner aspect of the plasmalemma similar to that in AMs. It is strongly suggested that muscle contractile activity plays an important role in the continuous and even distribution of dystrophin at the sarcolemma during development.
到目前为止，尚未有关于神经支配和收缩活动对培养的人类肌肉中肌营养不良蛋白表达影响的发育研究。我们对来自正常和杜兴氏肌营养不良症（DMD）活检肌肉的胎儿大鼠脊髓与无神经支配培养的非收缩性（AMs）和神经支配的持续收缩横纹肌人类肌纤维（ICMs）进行了肌营养不良蛋白定位的免疫细胞化学研究。在正常AMs中，成肌细胞和一些未成熟AMs显示肌营养不良蛋白染色阴性，但许多AMs在质膜下区域有肌营养不良蛋白的斑片状（不连续）分布，在肌膜附近和更深的细胞质中有一些颗粒状。在正常ICMs中，肌营养不良蛋白连续定位在肌膜内侧，在某些区域检测到一些周期性致密模式。来自DMD的AMs和ICMs肌营养不良蛋白染色均为阴性。为了研究肌肉收缩活动对肌营养不良蛋白分布的影响，我们从肌肉收缩首次出现起用河豚毒素（TTX）使ICMs麻痹两周。在麻痹的神经支配肌肉（PIMs）中，肌营养不良蛋白在质膜内侧仍呈斑片状（不连续）模式，类似于AMs中的模式。强烈提示肌肉收缩活动在发育过程中对肌营养不良蛋白在肌膜上的连续且均匀分布起重要作用。
