The effects of temperature on muscle energy liberation (heat plus work production) and isometric twitch force production were measured at rest length (l o) and at long muscle lengths (approx. 1.35 l o) where twitch force was greatly depressed. 2. Force production and energy liberation at l o declined progressively as muscle temperature was elevated from 0 to 20 degrees C. Force production decreased to a greater extent than did energy liberation. A plot of energy liberation vs. twitch force suggested that a fraction of the l o energy liberation was produced independent of temperature. 3. The energy liberated at long muscle lengths, the activation heat, was independent of muscle temperature. The activation heat is interpreted as reflecting the energy dissipated during Ca2+ cycling and thus suggests that, under the conditions of these experiments, the amount of Ca2+ released with stimulation is independent of muscle temperature and subsequent muscle force production. 4. Analysis of the results also supports the conclusions that skeletal muscle energy liberation is dependent on muscle force production and that the energy liberation associated with Ca2+ cycling is essentially independent of muscle length in the range of l o--1.35 l o.
摘要
在静息长度（l o）以及在肌肉长度较长（约为1.35 l o）下（此时抽搐力大幅降低），测量了温度对肌肉能量释放（热量加功产生）和等长抽搐力产生的影响。2. 当肌肉温度从0℃升高到20℃时，l o处的力产生和能量释放逐渐下降。力产生的下降幅度大于能量释放。能量释放与抽搐力的关系图表明，l o处的一部分能量释放与温度无关。3. 在长肌肉长度下释放的能量，即激活热，与肌肉温度无关。激活热被解释为反映Ca2+循环过程中耗散的能量，因此表明，在这些实验条件下，刺激时释放的Ca2+量与肌肉温度及随后的肌肉力产生无关。4. 对结果的分析还支持以下结论：骨骼肌能量释放取决于肌肉力产生，并且在l o至1.35 l o范围内，与Ca2+循环相关的能量释放基本与肌肉长度无关。
