Spatial and temporal aspects of ACh-induced [Ca2+]i oscillations in porcine tracheal smooth muscle
Spatial and temporal aspects of ACh-induced [Ca2+]i oscillations in porcine tracheal smooth muscle
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DOI：
10.1054/ceca.1999.0106
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发表时间：
2000-03-01
期刊：
影响因子：
4
通讯作者：
Sieck, GC
中科院分区：
文献类型：
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作者：
Prakash, YS;Pabelick, CM;Sieck, GC
本研究探讨了乙酰胆碱（ACh）诱导的猪气管平滑肌（TSM）细胞内局部钙离子浓度（[Ca 2 +]（i））升高与整体细胞反应的关系。使用实时共聚焦显微镜在加载fluo-3的TSM细胞中测量[Ca 2 +]（i）的区域（类似于1.5 μ m（3））和全局（全细胞）变化。区域响应表现为传播[Ca 2 +]（i）振荡，而全球响应反映了这些区域响应的时空整合。在一个区域内，[Ca 2 +]（i）振荡是“双相”的初始较高的频率，其次是较慢的稳态振荡。随着ACh浓度的增加，区域[Ca 2 +]（i）振荡的峰值（相对于0 nM的最大值）保持相对恒定，而频率和传播速度都增加。相反，区域振荡反应的整体时空整合表现为峰值和平均细胞[Ca 2 +]（i）的浓度依赖性增加。ACh诱导的[Ca ~（2+）]（i）振荡的意义在于通过调节振荡频率和传播速度来建立较慢的Ca ~（2+）依赖性生理过程的平均[Ca ~（2+）]（i）水平。(C)2000年哈考特出版社有限公司
This study evaluated the relationship between regional elevation in intracellular calcium concentration ([Ca2+](i)) induced by acetylcholine (ACh) and the global cellular responses in porcine tracheal smooth muscle (TSM) cells. Regional (similar to 1.5 mu m(3)) and global (whole cell) changes in [Ca2+](i) were measured in fluo-3 loaded TSM cells using real-time confocal microscopy. Regional responses appeared as propagating [Ca2+](i) oscillations whereas global responses reflected the spatiotemporal integration of these regional responses. Within a region, [Ca2+](i) oscillations were 'biphasic' with initial higher frequencies, followed by slower steady-state oscillations. With increasing ACh concentration, the peak (maximum value relative to 0 nM) of regional [Ca2+](i) oscillations remained relatively constant, whereas both frequency and propagation velocity increased. In contrast, the global spatiotemporal integration of the regional oscillatory responses appeared as a concentration-dependent increase in peak as well as mean cellular [Ca2+](i). We conclude that the significance of ACh-induced [Ca2+](i) oscillations lies in the establishment of mean [Ca2+](i) level for slower Ca2+-dependent physiological processes via modulation of oscillation frequency and propagation velocity. (C) 2000 Harcourt Publishers Ltd.