Orthologous myosin isoforms and scaling of shortening velocity with body size in mouse, rat, rabbit and human muscles
Orthologous myosin isoforms and scaling of shortening velocity with body size in mouse, rat, rabbit and human muscles
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DOI：
10.1113/jphysiol.2002.027375
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发表时间：
2003-02-01
影响因子：
5.5
通讯作者：
Bottinelli, R
中科院分区：
文献类型：
--
作者：
Pellegrino, MA;Canepari, M;Bottinelli, R
测定了兔和小鼠后肢骨骼肌单纤维的最大缩短速度(V-0)，并按肌球蛋白重链(MHC)亚型组成进行了分类。在相同的实验条件下，将兔和小鼠的V-0值与之前在人和大鼠身上获得的值进行了比较。不同物种含有相应肌球蛋白亚型的纤维之间的V-0存在显著差异：一般来说，每种亚型的V-0随体质量的增加而减小。对小鼠、大鼠、兔和人的比目鱼肌和胫前肌的肌球蛋白亚型分布进行了分析：慢肌球蛋白的比例一般随着身体尺寸的增加而增加。相应肌球蛋白亚型的V-0和相应肌肉的不同肌球蛋白亚型组成之间的差异决定了整个肌肉的缩短速度与身体大小的比例，这对于优化运动是必不可少的。用从四个物种的单个肌纤维中提取的肌球蛋白测定肌动蛋白在体外运动试验中的转位速度(V-f)：不同物种的肌球蛋白亚型之间以及不同物种之间相应的肌球蛋白亚型之间存在显著差异。每种肌球蛋白亚型的V-0和V-f值显著相关，有力地支持了肌球蛋白亚型表达是肌肉纤维最大缩短速度的主要决定因素的观点。
Maximum shortening velocity (V-0) was determined in single fibres dissected from hind limb skeletal muscles of rabbit and mouse and classified according to their myosin heavy chain (MHC) isoform composition. The values for rabbit and mouse V-0 were compared with the values previously obtained in man and rat under identical experimental conditions. Significant differences in V-0 were found between fibres containing corresponding myosin isoforms in different species: as a general rule for each isoform V-0 decreased with body mass. Myosin isoform distributions of soleus and tibialis anterior were analysed in mouse, rat, rabbit and man: the proportion of slow myosin generally increased with increasing body size. The diversity between V-0 of corresponding myosin isoforms and the different myosin isoform composition of corresponding muscles determine the scaling of shortening velocity of whole muscles with body size, which is essential for optimisation of locomotion. The speed of actin translocation (V-f) in in vitro motility assay was determined with myosins extracted from single muscle fibres of all four species: significant differences were found between myosin isoforms in each species and between corresponding myosin isoforms in different species. The values of V-0 and V-f determined for each myosin isoform were significantly correlated, strongly supporting the view that the myosin isoform expressed is the major determinant of maximum shortening velocity in muscle fibres.