Gregory J E, Luff A R, Morgan D L, Proske U
Pflugers Arch. 1978 Jul 18;375(2):207-11. doi: 10.1007/BF00584245.
Experiments were carried out to compare the stiffness of cross-bridges in amphibian slow and twitch muscle. An isolated iliofibularis muscle was subjected to rapid, small stretches during contraction of either slow or twitch fibres at a number of different isometric tensions. The method of analysis allowed the compliance of the cross-bridges to be distinguished from other sources of compliance. Provided that the muscle was stretched sufficinetly rapidly to obtain limiting values of stiffness, little difference was found between the mechanical properties of the cross-bridges in slow and twitch muscle. It is concluded that the difference in observed stiffness of the two muscle types is due to a lower turnover rate of cross-bridges and a smaller number of sarcomeres in slow fibres.
开展了实验以比较两栖动物慢肌和快肌中横桥的刚度。在不同等长张力下，于慢肌纤维或快肌纤维收缩期间，对一块分离的髂腓肌进行快速、小幅拉伸。分析方法能够区分横桥的顺应性与其他顺应性来源。倘若肌肉拉伸速度足够快以获得刚度极限值，慢肌和快肌中横桥的力学特性几乎没有差异。得出的结论是，两种肌肉类型观察到的刚度差异是由于慢肌纤维中横桥的转换率较低以及肌节数量较少。
