Mechanics and crossbridge kinetics of tracheal smooth muscle in two inbred rat strains
Mechanics and crossbridge kinetics of tracheal smooth muscle in two inbred rat strains
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DOI：
10.1183/09031936.03.00064203
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发表时间：
2003-08-01
影响因子：
24.3
通讯作者：
Lecarpentier, Y
中科院分区：
文献类型：
--
作者：
Blanc, FX;Coirault, C;Lecarpentier, Y
本研究的目的是确定近交系FisherF-344大鼠品系的非特异性在体气道高反应性是否与气管平滑肌（TSM）内在收缩特性的差异有关。（每个n=10）进行了研究，并在两个菌株的肌球蛋白交联（CB）的数量，力和动力学计算使用Huxley的方程适用于nonsarcomeric肌肉。Fisher大鼠的最大无负荷缩短速度和肌肉缩短的最大程度高于刘易斯大鼠（分别为-46%和-42%），而峰值等长张力相似。双曲线力/速度关系的曲率在不同菌株之间没有差异。两种菌株的肌球蛋白CB数和单位力相似。在Fisher大鼠中，CB脱离和附着的持续时间比刘易斯大鼠短（分别为-46%和-34%）。在Fisher大鼠中，这些结果表明，遗传决定的气道高反应性因素与横桥动力学的变化相关，有助于增加气管平滑肌缩短能力和速度。
The aim of the study was to determine whether the nonspecific in vivo airway hyperresponsiveness of the inbred Fisher F-344 rat strain was associated with differences in the intrinsic contractile properties of tracheal smooth muscle (TSM) when compared with Lewis rats.Isotonic and isometric contractile properties of isolated TSM from Fisher and Lewis rats (each n=10) were investigated, and myosin crossbridge (CB) number, force and kinetics in both strains were calculated using Huxley's equations adapted to nonsarcomeric muscles. Maximum unloaded shortening velocity and maximum extent of muscle shortening were higher in Fisher than in Lewis rats (-46% and -42%, respectively), whereas peak isometric tension was similar.The curvature of the hyperbolic force/velocity relationship did not differ between strains. Myosin CB number and unitary force were similar in both strains. The duration of CB detachment and attachment was shorter in Fisher than in Lewis rats (-46% and -34%, respectively).In Fisher rats, these results show that inherited, genetically determined factors of airway hyperresponsiveness are associated with changes in crossbridge kinetics, contributing to an increased tracheal smooth muscle shortening capacity and velocity.