Harris D J, Bennett P B
J Appl Physiol Respir Environ Exerc Physiol. 1983 May;54(5):1209-15. doi: 10.1152/jappl.1983.54.5.1209.
The contraction peak force (CPF) and contraction time (CT) of the soleus Hoffmann (H) reflex and motor (M) response muscle twitch were measured in three subjects during the 686-m seawater Atlantis III simulated dive at Duke University. The mean CPF of both H and M twitches was observed to be 40-60% larger during compression than in predive control studies (P less than 0.001 for M response). This effect was sustained during the first 300 m of decompression, while postdive values were normal. Rate of contraction, as measured by changes in CT, was slowed significantly but only during compression (by 23% in the H reflex at 66.4 bar, P less than 0.001). These marked effects in CPF and CT cannot be explained by the small increases observed in the muscle action potential latency and duration, or other neuronal mechanisms. It is concluded that the twitch contraction of skeletal muscle is significantly slowed and augmented at pressure due to changes in excitation-contraction coupling or in the contractile process itself. These findings may be of importance in interpreting the etiology of many neuromuscular signs of the high-pressure neurological syndrome.
在杜克大学进行的686米海水亚特兰蒂斯三号模拟潜水过程中，测量了三名受试者比目鱼肌霍夫曼（H）反射和运动（M）反应肌肉抽搐的收缩峰值力（CPF）和收缩时间（CT）。观察到在加压期间，H和M抽搐的平均CPF比潜水前对照研究中的值大40%-60%（M反应P<0.001）。在减压的前300米期间这种效应持续存在，而潜水后的值正常。通过CT变化测量的收缩速率显著减慢，但仅在加压期间减慢（在66.4巴时H反射减慢23%，P<0.001）。CPF和CT中的这些显著效应无法用肌肉动作电位潜伏期和持续时间的微小增加或其他神经元机制来解释。得出的结论是，由于兴奋-收缩偶联或收缩过程本身的变化，骨骼肌的抽搐收缩在压力下显著减慢并增强。这些发现对于解释高压神经综合征的许多神经肌肉体征的病因可能具有重要意义。
