Structure-function relationships of Ca spark activity in normal and failing cardiac myocytes as revealed by flash photography
Structure-function relationships of Ca spark activity in normal and failing cardiac myocytes as revealed by flash photography
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DOI：
10.1016/j.ceca.2006.05.006
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发表时间：
2007-02-01
期刊：
影响因子：
4
通讯作者：
Haworth, Robert A.
中科院分区：
文献类型：
--
作者：
Meethal, Sivan Vadakkadath;Potter, Katherine T.;Haworth, Robert A.
我们描述了在生理条件下，在离体心肌细胞的兴奋诱导的钙梯度的二维成像，使用一种新的方法，闪光摄影的fluo-3荧光。该方法可用于显示快速触发的Ca释放事件的空间分布和再现性，以及它们与底层结构的关系。在正常大鼠心肌细胞中，钙火花是明显的刺激后6毫秒出现从周围的t-小管，判断与二-8-ANEPPS染色的共定位。火花图案中的间隙与di-8-ANEPPS染色中的间隙一致。先前被鉴定为溶酶体的双极性fluo-3摄取在一些间隙中是突出的，这表明可能是t-小管周转的区域。在正常犬心肌细胞中，钙火花的搏动间方差非常低，t管空隙小，钙梯度迅速解决。在由快速起搏诱导的失败犬的肌细胞中，观察到钙瞬变减少与没有火花和t-小管的区域增加以及更大的心跳间火花方差相关。这些异常导致火花的非均匀空间分布，导致刺激后持续更长时间的细胞内钙梯度。这样的Ca梯度可引起不均匀收缩并导致收缩失败。(c)2006爱思唯尔有限公司保留所有权利。
We describe the two-dimensional imaging of excitation-induced Ca gradients in isolated myocytes under physiological conditions, using a novel method of flash photography of fluo-3 fluorescence. This method is useful for showing the spatial distribution and reproducibility of rapidly triggered Ca release events, and their relationship to underlying structures. In normal rat myocytes, Ca sparks were evident 6 ms after stimulation emerging from around t-tubules, as judged by co-localization with di-8-ANEPPS staining. Gaps in the spark pattern coincided with gaps in di-8-ANEPPS staining. Vacuolar fluo-3 uptake, previously identified as lysosomal, was prominent in some of the gaps, suggesting possible areas of t-tubule turnover. In normal dog myocytes, the beat-to-beat variance of Ca sparks was very low, t-tubular voids were small, and Ca gradients resolved rapidly. In myocytes from dogs with failure induced by rapid pacing, a reduced Ca transient was observed associated with increased areas that were void of sparks and t-tubules, and a greater beat-to-beat spark variance. These abnormalities resulted in a non-uniform spatial distribution of sparks, leading to Ca gradients across the cell that persisted for longer times after stimulation. Such Ca gradients could cause heterogeneous contraction and contribute to contractile failure. (c) 2006 Elsevier Ltd. All rights reserved.