REGENERATION OF SINGLE SKELETAL-MUSCLE FIBERS INVITRO
REGENERATION OF SINGLE SKELETAL-MUSCLE FIBERS INVITRO
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DOI：
10.1002/ar.1091820207
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发表时间：
1975-01-01
影响因子：
--
通讯作者：
BISCHOFF, R
中科院分区：
文献类型：
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作者：
BISCHOFF, R
建立了一种成年大鼠骨骼肌纤维培养体系，用于研究肌肉再生过程中单核成肌细胞的起源和行为。从300-400 gm大鼠的腿和大腿肌肉中手动取出单纤维，并在体外保持包埋在覆盖有培养基的纤维蛋白凝块中。通过连续观察培养的纤维来监测再生事件。在体外的最初几个小时内，纤维发生退行性变化，包括肌原纤维收缩凝块的形成和肌核固缩。肌内膜管（基底层）沿整个肌纤维长度保持完整沿着，并形成桥接收缩凝块的透明腔室。单纤维不含肌内膜细胞，除切断端外，在培养中无细胞生长。与此相反，肌内膜结缔组织细胞的丰富的产物被发现与束组成的两个或更多的纤维。分离的单核细胞，推测是肌肉卫星细胞，在培养期开始时存在于单纤维的肌内膜管内。没有证据表明肌核有助于单核细胞的形成。在体外培养的第二天，卫星细胞扩大并开始增殖，在肌内膜管内形成推定的成肌细胞克隆。早期克隆的细胞倍增时间约为22小时，并表现出有丝分裂同步性。在体外培养5-7天后，卫星细胞后代开始融合，在原始纤维的肌内膜管内形成多核肌管。肌管显示自发性收缩活动，并可延伸至整个肌内膜管的长度。
A culture system utilizing single skeletal muscle fibers from adult rats was developed to study the origin and behavior of mononucleated myoblasts during muscle regeneration. The single fibers are removed manually from the leg and thigh muscles of 300–400 gm rats and maintained in vitro embedded in a fibrin clot overlain with culture medium. Regenerative events were monitored by continuous observation of the cultured fibers. During the first few hours in vitro the fibers undergo degenerative changes including the formation of myofibrillar contraction clots and pyknosis of myonuclei. The endomysial tube (basement lamina) remains intact along the entire length of the fiber and forms transparent chambers bridging the contraction clots. Single fibers are free of endomysial cells and display no cellular outgrowth in culture, except at the cut ends. In contrast, a rich outgrowth of endomysial connective tissue cells is found with bundles consisting of two or more fibers. Isolated mononucleated cells, presumed to be muscle satellite cells, are present within the endomysial tube of single fibers at the onset of the culture period. There is no evidence that myonuclei contribute to the formation of mononucleated cells. The satellite cells enlarge and begin to proliferate during the second day in vitro to form clones of presumptive myoblasts within the endomysial tube. The early clones have a cell doubling time of about 22 hours and exhibit mitotic synchrony. After 5–7 days in vitro the satellite cell progeny begin to fuse to from multinucleated myotubes within the endomysial tube of the original fiber. The myotubes display spontaneous contractile activity and may extend throughout the length of the endomysial tube.