摘要
目的:观察家兔腓肠肌失神经支配后肌纤维在退行性变与修复性再生过程中超微结构的变化,探讨失神经支配骨骼肌修复性再生障碍的机制。方法:实验于2005-04/2006-04在南方医科大学中心实验室完成。选择成年新西兰大白兔20只,切断一侧胫神经腓肠肌肌支,术后1,4,8,12,16周分别采用耳缘静脉注射空气处死4只。取实验侧和对照侧腓肠肌内侧头肌组织少许,用于制备超薄切片标本,透射电镜观察各时间点兔失神经腓肠肌肌纤维形态。结果:纳入动物20只,均进入结果分析。①正常家兔腓肠肌肌原纤维排列整齐,肌小节和Z线清晰,线粒体均匀分布在肌原纤维之间,排列规则,细胞核位于质膜周边,未见溶酶体。②失神经支配1周,肌原纤维排列基本整齐,线粒体增多,无明显肿胀。③失神经支配4周,线粒体明显增多肿胀,部分线粒体空泡样变,溶酶体增多,Z线模糊,肌原纤维间隙增大。④失神经支配8周,肌纤维明显萎缩退行性变,大部分肌原纤维消失,残留的肌原纤维变得模糊,间隙增大,肌小结丧失正常的结构,胞浆内含有大量空泡变性的细胞器,可发现畸形核,染色质浓缩、边集,肌细胞膜极度皱缩。镜下发现较多的位于基膜下活化的肌卫星细胞,细胞内含有发达的粗面内质网和丰富的胞浆。一些肌卫星细胞直接与肌纤维融合。同时在间质中可发现一些形态上很象成纤维细胞的细胞,不过这些细胞含有大量的粗面内质网,胞浆内有颗粒和微丝,少量的圆形的线粒体。在退行性变的肌纤维基膜下也可发现肌管样结构的再生肌细胞,在这些肌管内一些肌丝在一起聚集成束,没有组装成肌原纤维,没有正常的肌小结结构。在它们周围有细小的空肌管样结构,可能是以往再生的肌细胞退行性变后的残余体。在间质中可发现一些细小的肌纤维。⑤失神经支配12周,大部分肌纤维萎缩退行性变,但�
AIM： To discuss the mechanism of the impeded myogenesis of denervated muscle by observing the ultrastructural changes of denervated rabbit gastrocnemius.
METHODS： The experiment was conducted at the Central Laboratory of Southern Medical University from April 2005 to April 2006. The nerves to the gastrocnemius of 20 adult Zelanian rabbits were resected, and 4 gastrocnemius samples were obtained from the executed rabbits by air injection respectively at the 1^st, 4^th, 8^th, 12^th and 16^th weeks after the operation. Some muscular tissues were obtained from gastrocnemius muscle of the experimental side and control side to prepare for ultrathin section, and the muscle fibers of denervated rabbit gastrocnemius at each time point were studied under the transmission electron microscope.
RESULTS; A total of 20 enrolled rabbits were involved in the analysis of results.① Normal gastrocnemius muscle fibers of the rabbit were orderly arranged; The sarcomere and ＂Z＂ line could be seen Clearly, and the mitochondria was arranged orderly beside the myofibris. The nucleolus located near the cell membranes without cytolysosome. ② At 1 week after denervation, the muscular fibril were in order arrangement with increased mitochondria, while no obvious tumid mitochondria could be found. ③ At 4 weeks after denervation, the mitochondda obviously increased and swelled with partial vacuole degenerative mitochondria, and the cytolysosome increased, and the ＂Z＂ line became blurry. The space between the myofibris became greater. ④ At 8 weeks after denervation, the myofibris began to degenerate and most of them disappeared： The rudimentary myofibris became blurry with the gaps increased with a great quantity of vacuolar degenerated cell organs in the cytoplasm. Abnormal nuclear could be found, and the chromatin condensed, and the membrane of myocyte greatly condensed. Lots of activated satellite cells were found under the basal lamina, and there were well-developed rough endoplasmic reticulum （RER） and abundant
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2007年第2期317-320,T0002,共5页
Journal of Clinical Rehabilitative Tissue Engineering Research
