Rome L C, Loughna P T, Goldspink G
Am J Physiol. 1984 Aug;247(2 Pt 2):R272-9. doi: 10.1152/ajpregu.1984.247.2.R272.
These experiments were performed to determine how ectothermal animals maintain their locomotory ability during acute changes in muscle temperature, despite the large thermal dependence of the mechanical properties of their muscle. The electrical activity of the red (slow-twitch) and white (fast-twitch) muscle fibers of carp was monitored while the carp swam at various speeds at 10 and 20 degrees C. The patterns of recruitment of different fiber types were similar at both temperatures. At low speeds only the red muscle was active, whereas at high speeds the white muscle was active as well. The swimming velocity at which white muscle was initially recruited increased from 26 cm/s at 10 degrees C to 46 cm/s at 20 degrees C. These results suggest that the order of recruitment of motor units was the same at 10 and 20 degrees C but that the recruitment occurred over a narrower range of speeds at the low temperature. Hence, to generate the muscle power required to swim at a certain velocity, fish recruit more muscle fibers, which include faster fiber types when their muscle is cold than when their muscle is warm.
进行这些实验是为了确定变温动物如何在肌肉温度急剧变化期间保持其运动能力，尽管其肌肉力学特性对温度有很大依赖性。当鲤鱼在10摄氏度和20摄氏度下以不同速度游动时，监测其红色（慢肌纤维）和白色（快肌纤维）肌肉纤维的电活动。在这两个温度下，不同纤维类型的募集模式相似。在低速时只有红色肌肉活跃，而在高速时白色肌肉也活跃。白色肌肉最初被募集时的游泳速度从10摄氏度时的26厘米/秒增加到20摄氏度时的46厘米/秒。这些结果表明，运动单位的募集顺序在10摄氏度和20摄氏度时是相同的，但在低温时募集发生的速度范围更窄。因此，为了产生以一定速度游泳所需的肌肉力量，鱼类会募集更多的肌肉纤维，当它们的肌肉寒冷时比温暖时包括更快的纤维类型。
