An instanteneous View of Contracting Muscle Captured by Rapid Freezing.

研制了一种新型的液氦冷冻系统。甘油处理的兔腰大肌肌纤维在等张收缩、僵直、松弛和等长收缩状态下快速冻结。使用该系统，将收缩肌肉的冷冻替换图像和冷冻蚀刻复制品图像与僵直和放松肌肉的图像进行了比较。结果表明，在肌肉收缩过程中，大多数肌球蛋白头部沿细丝轴向排列，间距为143A，这种排列可能是肌肉收缩过程中产生力所必需的。这些事实也意味着需要考虑一种新的收缩机制，因此我们提出了一种用于肌肉收缩的静电直线电机模型。

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.