骨骼肌兴奋-收缩偶联超微结构瞬时变化研究

目的：从毫秒级功能不变水平实时观察骨骼肌在潜伏期内的细胞超微结构形态变化。方法：采用双向红外线探测器－计算机控制的电刺激与超代温快速冷冻固定同步技术，对电刺激后的蟾蜍腓肠肌组织作快速冷冻固定，采用透射电镜对该肌在电后０．８，５．６，８．４ｍｓ及静息期的超微结构变化进行对比研究。

Study on the instant changes of ultrastructural morphological during excitation-contraction coupling in skeletal muscles

Objective:To study the ultrastructural morphological changes at millisecond time course level in skeletal muscle during excitation contraction coupling after electrical stimulation. Methods: Two way infrared detectors with a computer to control the signal of electric stimulation and quick freezing fixation were employed in this test. The ultrastructure of toad skeletal muscle was studied by transmission electronic microscopy after its skeletal muscle was stimulated in 0.8, 5.6, 8.4 ms. The skeletal muscular ultrastructure at known millisecond time course were observed following quick freezing after a single electrical stimulation. Results:The space between sarcolemma and muscle myofibril was strikingly narrowed from 0.8 ms to 8.4 ms after electric stimulation, and 2 holes were observed in the front of sarcoplasmic reticulum membrane at the same time. Conclusion: During excitation contraction coupling, the sarcolemma has positional shaft and space changes with myofibril when depolarization occurs, besides, there are small holes on the sarcolemma when skeletal muscles contract.