An instanteneous View of Contracting Muscle Captured by Rapid Freezing.

研制了一种新的液氦冷冻系统。甘油化兔腰大肌肌纤维在等张收缩状态下以及在僵直、松弛和等长收缩状态下快速冷冻。使用该系统，冷冻替代图像和冷冻蚀刻复制图像的收缩肌肉与僵硬和放松的肌肉。结果使我们得出结论，在肌肉收缩期间，大多数肌球蛋白头沿轴向沿着细丝以143 A的间距排列，并且这种肌球蛋白头的排列可能是收缩期间产生力所必需的。这些事实也意味着一个新的收缩机制应该考虑，所以我们在这里提出了一个静电直线电机模型的肌肉收缩。

A new freezing system using liquid helium was developed. Glycerinated rabbit psoas muscle fiber was rapidly frozen under isotonic contraction as well as in rigor, relaxation and isometric contraction states. Using this system, freeze-substituted images and freeze-etch replica images of contracting muscle were compared with those of rigor and relaxed muscle. The results lead us to conclude that, during muscle contraction, most of the myosin heads are arranged axially along thin filaments with a spacing of 143 A and that this arrangement of myosin heads may be required for force generation during contraction. These facts also mean a new contraction mechanism shoud be considered, so we propose here a electrostatic linear motor model for muscle contraction.