Myosin subunits and contractile properties of single fibers from hypokinetic rat muscles.
Myosin subunits and contractile properties of single fibers from hypokinetic rat muscles.
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肌球蛋白亚基和运动功能减退大鼠肌肉单纤维的收缩特性。
DOI：
10.1152/jappl.1987.63.6.2293
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Moss,RL
中科院分区：
文献类型：
--
作者：
Reiser,PJ;Kasper,CE;Moss,RL
本实验观察了长时间运动功能减退对成年大鼠后肢悬吊28天后，足底快缩肌（PL）和比目鱼肌慢缩肌（SOL）协同肌纤维收缩特性和肌球蛋白同工酶的影响。有一个31%的增加，从SOL的纤维之间的平均最大无负荷缩短速度（Vmax）没有变化的平均Vmax从PL后悬浮。肌球蛋白重链和轻链（MHC和MLC）组成的束和MHC组成的单纤维从控制和悬挂的肌肉进行了检查，使用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳。运动减退SOL中快型MHC的相对量显著增加，PL中快型MHC的量增加较小。在运动功能减退期间，MLC发生了相对较小的变化。随着Vmax在来自控制和悬挂肌肉的单个纤维中增加，快速型MHC的相对量增加。结果表明，骨骼肌肌球蛋白同工酶组成，特别是重链，在运动减少，这一发现提供了一个解释的变化，在相同条件下，大鼠单肌纤维的Vmax。
The effects of prolonged hypokinesia on the contractile properties and myosin isozymes of single fibers from the synergistic fast-twitch plantaris (PL) and slow-twitch soleus (SOL) skeletal muscles of adult rats were studied after 28 days of hindlimb suspension. There was a 31% increase in the mean maximal velocity of unloaded shortening (Vmax) among fibers from SOL with no change in the mean Vmax of fibers from PL after suspension. The myosin heavy and light chain (MHC and MLC) composition of bundles and the MHC composition of single fibers from control and suspended muscles were examined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. There was a marked increase in the relative amount of fast-type MHC's in hypokinetic SOL and a smaller increase in the amount of fast-type MHC's in the PL. Relatively minor changes occurred in the MLC's during hypokinesia. As Vmax increased among individual fibers from control and suspended muscles, the relative amount of fast-type MHC's increased. The results demonstrate that the myosin isozyme composition of skeletal muscle, especially the heavy chains, is altered during hypokinesia, and this finding provides an explanation for changes in Vmax of rat single muscle fibers under the same conditions.