Abnormalities in structure and function of limb skeletal muscle fibres of dystrophic mdx mice
Abnormalities in structure and function of limb skeletal muscle fibres of dystrophic mdx mice
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营养不良mdx小鼠四肢骨骼肌纤维结构和功能异常
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
D. Stephenson
中科院分区：
文献类型：
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作者：
S. Head;D. Williams;D. Stephenson
在这项研究中，我们已经证明成年（大于26周）mdx小鼠的骨骼肌纤维有明显的结构畸形。我们已经在mdx小鼠中描述了这一特征的发病和年龄依赖性。这些变形的三维结构已经在孤立的纤维中可视化，这些变形的方向在肌肉中通过共聚焦激光扫描显微镜确定。我们还发现，纤维较长的肌肉（指长伸肌（edl）和比目鱼肌，长6-7.3毫米）比纤维较短的肌肉（指短屈肌（f d b），长0.3-0.4米）更容易出现形态异常的纤维。在研究的肌肉中也发现了一种后退行性纤维，其中央和外周核沿纤维的长度共存。我们发现，轻度延长（偏心）收缩（肌肉在强直收缩期间拉伸12%）导致mdx edl肌随后产生的最大强直力显著降低。相比之下，正常比目鱼肌、正常edl肌和mdx比目鱼肌的最大强直力产生并未因该方案而改变。我们认为，变形的快速糖酵解纤维是在成人mdx肌中发现的，而不是在成人mdx比目鱼肌中发现的，这是由延长方案造成的纤维老化的群体。
In this study we have shown that the skeletal muscle fibres from adult (older than 26 weeks) mdx mice have gross structural deformities. W e have characterized the onset and age dependence of this feature in mdx mice. The three dimensional structure of these deformities has been visualized in isolated fibres and the orientation of these deform ities was determ ined w ithin the muscle by confocal laser scanning microscopy. We have also shown that the occurrence of morphologically abnormal fibres is greater in muscles w ith longer fibres (extensor digitorum longus (edl) and soleus, 6—7.3 mm long), than in muscles with shorter fibres (flexor digitorum brevis (f d b ), 0.3—0.4 m m long). A population of post-degenerative fibres, with both central and peripheral nuclei coexistent along the length of the fibre, has also been identified in the muscles studied. We showed that a mild protocol of lengthening (eccentric) contractions (the muscle was stretched by 12% during a tetanic contraction) caused a major reduction in the maximal tetanic force subsequently produced by mdx edl muscle. In contrast, maximal tetanic force production in normal soleus, normal edl and mdx soleus muscles was not altered by this protocol. We suggest that the deform ed fast glycolytic fibres which are found in adult mdx edl but not in adult mdx soleus muscles are the population of fibres dam aged by the lengthening protocol.
影响因子：
5.5
作者：
BROOKS, SV;FAULKNER, JA
通讯作者：
FAULKNER, JA