Modulation by caffeine of calcium-release microdomains in frog skeletal muscle fibers.
Modulation by caffeine of calcium-release microdomains in frog skeletal muscle fibers.
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DOI：
10.4067/s0716-97602006000300017
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发表时间：
2006
影响因子：
6.7
通讯作者：
J. Vergara;M. DiFranco
中科院分区：
文献类型：
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作者：
J. Vergara;M. DiFranco
用共聚焦斑点检测技术研究了咖啡因对两栖骨骼肌纤维兴奋-收缩偶联过程的影响。这种方法可以仔细区分咖啡因对三联体所在Z线上主要钙释放源的影响和对其他潜在钙释放源的次要作用。结果表明，0.5 mM咖啡因可增强和延长在Z线水平记录到的局部动作电位诱发的钙瞬变，而1 mM咖啡因仅能延长它们。这两种剂量的影响都是可逆的。在M线水平上，在1 mM咖啡因存在下，局部钙瞬变表现出比对照条件下更大的变异性。在这个剂量的咖啡因中，偶尔也可以观察到连接外的钙释放源。
The effects of caffeine on the process of excitation-contraction coupling in amphibian skeletal muscle fibers were investigated using the confocal spot detection technique. This method permits to carefully discriminate between caffeine effects on the primary sources of Ca2+ release at the Z-lines where the triads are located and secondary actions on other potential Ca Release sources. Our results demonstrate that 0.5 mM caffeine potentiates and prolongs localized action-potential evoked Ca2+ transients recorded at the level of the Z-lines, but that 1mM only prolongs them. The effects at both doses are reversible. At the level of the M-line, localized Ca2+ transients displayed more variability in the presence of 1 mM caffeine than in control conditions. At this dose of caffeine, extra-junctional sources of Ca2+ release also were observed occasionally.