Spark- and ember-like elementary Ca2+ release events in skinned fibres of adult mammalian skeletal muscle
Spark- and ember-like elementary Ca2+ release events in skinned fibres of adult mammalian skeletal muscle
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DOI：
10.1111/j.1469-7793.2001.00379.x
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发表时间：
2001-12-01
影响因子：
5.5
通讯作者：
Fink, RHA
中科院分区：
文献类型：
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作者：
Kirsch, WG;Uttenweiler, D;Fink, RHA
1. 使用激光扫描共聚焦显微镜，我们首次显示了成年哺乳动物肌肉化学和机械剥皮纤维中肌浆网的基本 Ca2+ 释放事件 (ECRE)，并将其与两栖动物剥皮纤维的 ECRE 进行了比较。2．可以从单个单皮哺乳动物纤维中测量到数百个自发发生的事件。除了类似火花的事件外，我们还发现了类似余烬的事件，即振幅稳定的长期事件。哺乳动物骨骼肌中这两种不同的基本释放类型可以在同一位置组合发生。3．哺乳动物骨骼肌ECRE出现频率的两个峰值与肌节内横管系统的预期位置一致，表明ECRE主要起源于三元连接处。4．成年哺乳动物肌肉中的 ECRE 也可以在机械剥皮纤维中膜去极化引起的全局 Ca2+ 释放开始时被识别。此外，ECRE 的频率通过应用 0.5 nim 咖啡因显着增加，并通过应用 2 nim 丁卡因降低。5。我们得出的结论是，成年哺乳动物肌肉中的兴奋-收缩耦合过程涉及火花和余烬样基本 Ca2+ 释放事件的激活。
1. Using laser scanning confocal microscopy, we show for the first time elementary Ca2+ release events (ECRE) from the sarcoplasmic reticulum in chemically and mechanically skinned fibres from adult mammalian muscle and compare them with ECRE from amphibian skinned fibres.2. Hundreds of spontaneously occurring events could be measured from individual single skinned mammalian fibres. In addition to spark-like events, we found ember-like events, i.e. long-lasting events of steady amplitude. These two different fundamental release types in mammalian skeletal muscle could occur in combination at the same location.3. The two peaks of the frequency of occurrence for ECRE of mammalian skeletal muscle coincided with the expected locations of the transverse tubular system within the sarcomere, suggesting that ECRE mainly originate at triadic junctions.4. ECRE in adult mammalian muscle could also be identified at the onset of the global Ca2+ release evoked by membrane depolarisation in mechanically skinned fibres, In addition, the frequency of ECRE was significantly increased by application of 0.5 nim caffeine and reduced by application of 2 nim tetracaine.5. We conclude that the excitation-contraction coupling process in adult mammalian muscle involves the activation of both spark- and ember-like elementary Ca2+ release events.