Passive stiffness changes in soleus muscles from desmin knockout mice are not due to titin modifications
Passive stiffness changes in soleus muscles from desmin knockout mice are not due to titin modifications
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DOI：
10.1007/s00424-002-0875-0
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发表时间：
2002-09-01
影响因子：
4.5
通讯作者：
Goubel, F
中科院分区：
文献类型：
--
作者：
Anderson, J;Joumaa, V;Goubel, F
被动刚度被认为是增加小鼠比目鱼肌缺乏结蛋白。由于肌联蛋白被认为是肌肉弹性的主要来源，因此肌联蛋白适应可能可以解释僵硬。为了测试这一点，通过使用各种延伸测试分析了来自结蛋白敲除小鼠和对照小鼠的比目鱼肌的单皮肤纤维的被动机械特性。用SDS-凝胶电泳研究Titin的表达。缺乏结蛋白并没有改变肌联蛋白条带的电泳迁移率（3700 kDa）或肌联蛋白和星云蛋白条带之间的光学密度单位比（等于0.3）和肌联蛋白和肌球蛋白重链条带之间的光学密度单位比（等于0.08）。纤维的弹性性质在结蛋白不存在的情况下没有改变，因为被动2张力在准静态（56-66 kN m（-2））和动态（100-118 kN m（-2））条件下是相似的，无论纤维的种类如何。因此，当结蛋白缺乏时，肌联蛋白不太可能导致整个比目鱼肌被动僵硬大幅增加。
Passive stiffness was found to be increased in mouse soleus muscles lacking desmin. Because titin is considered to be the major source of muscle elasticity, the stiffening might be explainable by titin adaptation. To test this, passive mechanical properties of single skinned fibres of soleus muscles from desmin knockout and control mice were analysed by using various extension tests. Titin expression was studied by SDS-gel electrophoresis. Absence of desmin did not modify either electrophoretic mobility of the titin band (3700 kDa) or optical density-unit ratios between bands for titin and nebulin (congruent to0.3) and bands for titin and myosin heavy chain (congruent to0.08). Elastic properties of fibres were not altered in the absence of desmin since passive 2 tensions were similar under quasi-static (56-66 kN m(-2)) and dynamic (100-118 kN m(-2)) conditions whatever the kind of fibre. Thus, titin is unlikely to be responsible for the large increase in passive stiffness observed in whole soleus muscles when desmin is lacking.