Non-hyperbolic force-velocity relationship in single muscle fibres.
Non-hyperbolic force-velocity relationship in single muscle fibres.
复制标题
单肌纤维中的非双曲力-速度关系。
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
B. Scubon
中科院分区：
文献类型：
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作者：
K. Edman;L. Mulieri;B. Scubon
本文研究了青蛙半腱肌16根单纤维的力-速度关系，特别注意曲线的高力部分。力-速度曲线是双曲线，除了在80%测得的等长张力（PO）附近的曲率反转。矩形双曲线拟合（线性，最小二乘法）这些数据以及只有当值低于0.78 PO被认为是。将这些双曲线外推至0.78 PO以上，得到预测的等长张力（P*O），平均比测量的PO值高32+/-6%。这些双曲线的希尔常数（1.84 ℃）为：a/P*O=0.177+/-0.021，B=0.329+/-0.035 M.L./秒，Vmax=1.91+/-0.074 M.L./秒逆转的曲率持续时，力-速度数据，获得使用：1或60分钟的响应间隔，后加载等渗反应，网格刺激，电诱导挛缩和束的纤维。当从轻微拉伸的纤维（约2.3 μ m肌节长度相比，2.1 μ m的控制）获得力-速度数据时，曲率的逆转减少。结果表明，肌节长度重新分布可能不占非双曲线的力-速度关系。基于收缩丝晶格的几何形状的行为的解释进行了讨论。
The force-velocity relation has been studied in sixteen single fibres from frog semitendinosus muscle with particular attention to the high-force portion of the curve. The force-velocity curve was hyperbolic except for a reversal of curvature near 80% measured isometric tension (PO). Rectangular hyperbolas fitted (linear, least-squares method) these data well only when values below 0.78 PO were considered. Extrapolation of these hyperbolas above 0.78 PO gave predicted isometric tensions (P*O) which averaged 32+/-6% above the measured PO values. Hill's constants (1.84 degrees C) for these hyperbolas were: a/P*O=0.177+/-0.021, b=0.329+/- 0.035 M.L./sec, Vmax=1.91+/-0.074 M.L./sec. The reversal of curvature persisted when force-velocity data were obtained using: 1 or 60 min response intervals, afterloaded isotonic responses, grid stimulation, electrically induced contractures and bundles of fibres. The reversal of curvature diminished when force-velocity data were obtained from slightly stretched fibres (about 2.3 mum sarcomere length as compared to 2.1 mum in the control). The results indicate that sarcomere length redistributions probably do not account for the non-hyperbolic force-velocity relation. An explanation for the behavior based on the geometry of the contractile filament lattice is discussed.