Mode of Ca2+ action on ciliary beat frequency in single ovine airway epithelial cells
Mode of Ca2+ action on ciliary beat frequency in single ovine airway epithelial cells
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DOI：
10.1111/j.1469-7793.1999.00851.x
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发表时间：
1999-11-01
影响因子：
5.5
通讯作者：
Bookman, RJ
中科院分区：
文献类型：
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作者：
Salathe, M;Bookman, RJ
1. 我们分析了细胞质钙（[Ca2+](i)）和纤毛搏动频率（CBF）之间耦合的动力学，同时使用单纤毛记录和单细胞[Ca2+](i)测量从培养的羊气管上皮细胞。在静止状态和10 μ M乙酰胆碱（ACh）激活g蛋白偶联M3毒蕈碱受体后，测量CBF和[Ca2+](i)（用fura-2表示）。对相衬显微镜下光强度3s数据段的傅里叶变换分析显示，在暴露于ACh的2分钟和随后的冲洗期间，[Ca2+](i)和CBF的变化之间没有明显的延迟。通过计算瞬时拍频提高了CBF时间分辨率。这表明CBF滞后于[Ca2+](i)响应ACh的快速增加，延迟小于1个拍周期（143 ms at 7 Hz）。当用改进的傅立叶方法估计CBF时，观察到该延迟为70 +/- 30 ms（平均+/- S.E.M.; n = 20纤毛）。在较慢的基线恢复过程中，观察到8 +/- 3.2 s的滞后，表明迟滞。虽然钙调素抑制剂（calmidazolium和W-7；每个n = 5）平均降低基线CBF 1.1 +/- 0.1 Hz，但它们没有改变[Ca2+](i)和CBF之间的动力学关系。同样，磷酸酶抑制剂（冈田酸和环孢素A，每个n = 5）既不改变基线CBF，也不改变[Ca2+](i)和CBF之间的动力学耦合。这些数据表明，Ca2+作用于羊气道上皮细胞CBF的时间，不太可能由涉及钙调蛋白或激酶/磷酸酶反应的磷酸化反应决定。提出了一种Ca2+刺激脑血流的简单模型。坑的。模型数据表明，四个或更多的Ca2+离子协同结合，以加速脑血流。
1. We analysed the kinetics of coupling between cytoplasmic calcium ([Ca2+](i)) and ciliary beat frequency (CBF) using simultaneous single cilium recording and single cell [Ca2+](i) measurements from cultured ovine tracheal epithelial cells.2. CBF and [Ca2+](i) (indicated by fura-2) were measured at rest and in response to activation of the G-protein coupled M3 muscarinic receptor by 10 mu M acetylcholine (ACh).3. Fourier transform analysis of 3s data segments of light intensity from phase-contrast microscopy showed no significant delay between changes in [Ca2+](i) and CBF during a 2 min exposure to ACh and subsequent washout.4. CBF time resolution was improved by computing instantaneous beat frequency. This revealed that CBF lagged the rapid increase in [Ca2+](i) in response to ACh with a delay of less than 1 beat cycle (143 ms at 7 Hz). When CBF was estimated by an improved Fourier method, this delay was observed to be 70 +/- 30 ms (mean +/- S.E.M.; n = 20 cilia). During the slower return to baseline, a lag of 8 +/- 3.2 s was observed, indicative of hysteresis.5. While calmodulin inhibitors (calmidazolium and W-7; each n = 5) decreased baseline CBF by an average of 1.1 +/- 0.1 Hz, they did not alter the kinetic relationship between [Ca2+](i) and CBF. Similarly, phosphatase inhibitors (okadaic acid and cyclosporin A; each n = 5), changed neither baseline CBF nor the kinetic coupling between [Ca2+](i) and CBF.6. These data suggest that the timing of Ca2+ action on CBF in ovine airway epithelial cells, is unlikely to be determined by phosphorylation reactions involving calmodulin or kinase/phosphatase reactions.7. A simple model for Ca2+ stimulation of CBF is presented. Pits of the. model to the data suggest four or more Ca2+ ions bind cooperatively to speed up CBF.