EXCITATION CONTRACTION COUPLING IN NORMAL AND MDX MICE
EXCITATION CONTRACTION COUPLING IN NORMAL AND MDX MICE
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DOI：
10.1002/mus.880130105
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发表时间：
1990-01-01
期刊：
影响因子：
3.4
通讯作者：
ROBSON, E
中科院分区：
文献类型：
--
作者：
HOLLINGWORTH, S;MARSHALL, MW;ROBSON, E
杜氏肌营养不良症患者和mdx小鼠的肌肉中不存在肌营养不良蛋白。最近的研究表明，肌营养不良蛋白位于表面膜和三联交界处，在那里它与横管膜有关。由于三联结是兴奋-收缩（EC）耦合的部位，我们研究了膜内电荷运动（EC耦合的一个步骤）是否因缺乏肌营养不良蛋白而改变。电荷运动被认为是由横管膜引起的，并且是肌浆网Ca2+释放对横管膜电位依赖的基础。我们发现，与正常小鼠相比，mdx小鼠肌肉中的膜内电荷运动或被动膜电特性没有差异。如果肌营养不良蛋白确实在EC偶联中起作用，那么这种作用可能是在电荷运动步骤之后发生的。
The protein dystrophin is absent from patients with Duchenne muscular dystrophy and from the muscles of mdx mice. Recent studies have shown that dystrophin is located at the surface membrane and at the triadic junction, where it is associated with the transverse tubular membrane. Since the triadic junction is the site of excitation-contraction (EC) coupling, we have investigated whether intramembrane charge movement, a step in EC coupling, is modified by the absence of dystrophin. Charge movements are thought to arise from the transverse tubular membrane and to underlie the dependence of sarcoplasmic reticulum Ca2+ release on transverse tubular membrane potential. We find no differences between intramembrane charge movements or passive membrane electrical properties measured in muscles from mdx mice compared with normal mice. If dystrophin does play a role in EC coupling, that role is likely to be subsequent to the charge movement step.