Spatial and temporal inhomogeneities during Ca2+ release from the sarcoplasmic reticulum in pig ventricular myocytes
Spatial and temporal inhomogeneities during Ca2+ release from the sarcoplasmic reticulum in pig ventricular myocytes
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DOI：
10.1161/01.res.0000045940.67060.dd
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发表时间：
2002-11-29
影响因子：
20.1
通讯作者：
Sipido, KR
中科院分区：
文献类型：
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作者：
Heinzel, FR;Bito, V;Sipido, KR
心室肌细胞在正常兴奋-收缩偶联期间的[Ca2+](i)瞬态是起源于肌浆网交界处的初级Ca2+释放事件的总和。（SR）和t管系统。对小型哺乳动物的研究表明，释放点密度很高，但对大型哺乳动物的研究却知之甚少。我们使用共聚焦显微镜研究了SR Ca2+释放在猪心室肌细胞中的空间分布。在107个细胞中的69个中，沿纵向扫描线观察到Ca2+释放的大不均匀性。[Ca2+](i)增加延迟的区域（达到峰值F/F-o（其中F表示荧光强度，F-o表示休息时的F）的50%的时间在延迟区域为26 +/- 1 ms，而在早期区域为11 +/- 2 ms）和更小(延迟区域的峰值F/F-o为2.27 +/- 0.10，而在早期区域为2.69 +/- 0.13;n=13个细胞，P
The [Ca2+](i) transient of ventricular myocytes during normal excitation-contraction coupling is the summation of primary Ca2+ release events, which originate at the junction of the sarcoplasmic reticulum. (SR) and the T-tubular system. Studies in small mammals have shown a high density of release sites, but little is known of larger mammals. We have studied the spatial distribution of SR Ca2+ release in pig ventricular myocytes using a confocal microscopy. In 69 of 107 cells, large inhomogeneities of Ca2+ release were observed along the longitudinal scan line. Areas where the increase of [Ca2+](i) was delayed (time to 50% of peak F/F-o [where F indicates fluorescence intensity, and F-o indicates F at rest] was 26 +/- 1 ms in delayed areas versus 11 +/- 2 ms in early areas) and smaller (peak F/F-o was 2.27 +/- 0.10 for delayed areas versus 2.69 +/- 0.13 for early areas; n=13 cells, P