Adaptations for extremely high muscular power output: why do muscles that operate at intermediate cycle frequencies generate the highest powers?
Adaptations for extremely high muscular power output: why do muscles that operate at intermediate cycle frequencies generate the highest powers?
复制标题
DOI：
10.1007/s10974-022-09640-2
复制
发表时间：
2023-06
影响因子：
2.7
通讯作者：
中科院分区：
文献类型：
--
作者：
蓝胸鹌鹑的胸肌在迄今为止测量的收缩周期中产生最高的功率输出，约为400 W kg− 1。在周期性收缩期间产生的功率是功和周期频率（或标准工作频率）的乘积，这表明高功率应该通过在高周期频率下工作而受到青睐。然而，鹌鹑肌肉以中间周期频率（23 Hz）运行，这远低于骨骼肌能够运行的最高频率（脊椎动物中约200 Hz）。为了理解这一明显的异常，在本文中，我认为，有利于高机械功率的适应，以及力和肌肉工作频率之间发生的权衡，限制功率。它将表明，适应，有利于快速周期性收缩妥协的力量产生，因此，最大功率增加与周期频率约15-25赫兹，但在更高的周期频率下降。在高循环频率下，通过降低横桥占空比和增加由非收缩性元件（如肌浆网和线粒体）占据的肌肉的比例来降低肌肉应力。适于产生高功率的肌肉，例如蓝胸鹌鹑的胸肌，表现出：（i）中等收缩动力学;（ii）高的相对肌原纤维体积;和（iii）高的最大缩短速度和相对平坦的力-速度关系。它们的特征还在于：（iv）以中间周期频率操作;（v）利用不对称长度轨迹，周期缩短的比例很高;以及，最后，（vi）相对较大的肌肉。在某种程度上，高功率输出的蓝胸鹌鹑胸肌可以归因于它的身体大小和中间翼拍频率所需的产生空气动力来支持身体质量，但此外，专业化的收缩和形态学特性的肌肉有利于在高应变率的高应力的产生。在线版本包含补充材料，可通过10.1007/s10974-022-09640-2获得。
The pectoralis muscles of the blue-breasted quail Coturnix chinensis generate the highest power output over a contraction cycle measured to date, approximately 400 W kg− 1. The power generated during a cyclical contraction is the product of work and cycle frequency (or standard operating frequency), suggesting that high powers should be favoured by operating at high cycle frequencies. Yet the quail muscles operate at an intermediate cycle frequency (23 Hz), which is much lower than the highest frequency skeletal muscles are capable of operating (~ 200 Hz in vertebrates). To understand this apparent anomaly, in this paper I consider the adaptations that favour high mechanical power as well as the trade-offs that occur between force and muscle operating frequency that limit power. It will be shown that adaptations that favour rapid cyclical contractions compromise force generation; consequently, maximum power increases with cycle frequency to approximately 15–25 Hz, but decreases at higher cycle frequencies. At high cycle frequencies, muscle stress is reduced by a decrease in the crossbridge duty cycle and an increase in the proportion of the muscle occupied by non-contractile elements such as sarcoplasmic reticulum and mitochondria. Muscles adapted to generate high powers, such as the pectoralis muscle of blue-breasted quail, exhibit: (i) intermediate contraction kinetics; (ii) a high relative myofibrillar volume; and (iii) a high maximum shortening velocity and a relatively flat force-velocity relationship. They are also characterised by (iv) operating at an intermediate cycle frequency; (v) utilisation of asymmetrical length trajectories, with a high proportion of the cycle spent shortening; and, finally, (vi) relatively large muscles. In part, the high power output of the blue-breasted quail pectoralis muscle can be attributed to its body size and the intermediate wing beat frequency required to generate aerodynamic force to support body mass, but in addition specialisations in the contractile and morphological properties of the muscle favour the generation of high stress at high strain rates. The online version contains supplementary material available at 10.1007/s10974-022-09640-2.
登录
查看更多内容
影响因子：
5.4
作者：
Lowi-Merri TM;Benson RBJ;Claramunt S;Evans DC
通讯作者：
Evans DC
DOI：
10.1152/ajpregu.00243.2002
发表时间：
2003-06-01
影响因子：
2.8
作者：
Girgenrath, M;Marsh, RL
通讯作者：
Marsh, RL
影响因子：
--
作者：
MARSH, RL;TAIGEN, TL
通讯作者：
TAIGEN, TL
影响因子：
5.5
作者：
Baylor, SM;Hollingworth, S
通讯作者：
Hollingworth, S
DOI：
10.1016/j.cub.2021.05.008
发表时间：
2021-07-26
期刊：
Current biology : CB
影响因子：
--
作者：
Adam I;Maxwell A;Rößler H;Hansen EB;Vellema M;Brewer J;Elemans CPH
通讯作者：
Elemans CPH