| 摘要: |
| 目的：从毫秒级功能变化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低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刺激后0.8,5.6,8.4ms及静息期的超微结构变化进行对比研究。结果：骨骼肌组织处于静息期时，其肌膜与肌纤维的间隙较宽，受电刺激后0.8ms开始至8.4ms，肌膜与肌细胞间的间隙大大变窄。并发现骨骼肌组织在电刺激后0.8，5.6及8.4ms时肌浆网前端的膜产生两个圆孔，而当骨骼肌处于静息期时肌浆网膜并无此形态结构。结论：当骨骼肌兴奋-收缩偶联发生时，肌膜在产生去极化的同时产生位移，并与肌纤维的间距发生改变；骨骼肌收缩时肌浆网膜出现小孔。 |
| 关键词: 骨骼肌 兴奋-收缩偶联 超微结构 |
| DOI： |
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| 基金项目: |
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| Study on the instant changes of ultrastructural morphological during excitation-contraction coupling in skeletal muscles |
| 夏金辉,余宏宇,叶煦亭,沙继宏,吴越,雷长海,杨勇骥 |
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| Abstract: |
| 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. |
| Key words: skeletal muscle excitation-contraction coupling ultrastructure |
