Nanosecond electric pulse-induced calcium entry into chromaffin cells
Nanosecond electric pulse-induced calcium entry into chromaffin cells
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DOI：
10.1016/j.bioelechem.2008.02.003
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发表时间：
2008-06-01
影响因子：
5
通讯作者：
Craviso, Gale L.
中科院分区：
文献类型：
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作者：
Vernier, P. Thomas;Sun, Yinghua;Craviso, Gale L.
将可电兴奋的牛肾上腺嗜铬细胞暴露于场强为 2 MV/m 至 8 MV/m 的纳秒持续时间的电脉冲，并通过负载钙绿的细胞的荧光成像实时监测细胞内钙水平 ([Ca2+](i))。单个 4 ns、8 MV/m 脉冲会产生快速、短暂的 [Ca2+](i) 增加，钙反应的幅度取决于电场的强度。多个脉冲未能产生比单个脉冲更大的钙反应，并且在触发 [Ca2+](i) 的另一个最大增加之前，脉冲之间需要较短的不应期。脉冲诱导的 [Ca2+](i) 升高不受 Co2+、咖啡因或毒胡萝卜素消耗细胞内钙储存的影响，但被细胞外介质中 EGTA 或 L 型钙通道阻滞剂尼群地平的存在完全阻止。因此，单个纳秒脉冲足以引起 [Ca2+](i) 升高，涉及钙通过 L 型钙通道进入。 (C) 2008 Elsevier B.V. 保留所有权利。
Electrically excitable bovine adrenal chromaffin cells were exposed to nanosecond duration electric pulses at field intensities ranging from 2 MV/m to 8 MV/m and intracellular calcium levels ([Ca2+](i)) monitored in real time by fluorescence imaging of cells loaded with Calcium Green. A single 4 ns, 8 MV/m pulse produced a rapid, short-lived increase in [Ca2+](i), with the magnitude of the calcium response depending on the intensity of the electric field. Multiple pulses failed to produce a greater calcium response than a single pulse, and a short refractory period was required between pulses before another maximal increase in [Ca2+](i) could be triggered. The pulse-induced rise in [Ca2+](i) Was not affected by depleting intracellular calcium stores with Co2+, caffeine or thapsigargin but was completely prevented by the presence of EGTA, or the L-type calcium channel blocker nitrendipine in the extracellular medium. Thus, a single nanosecond pulse is sufficient to elicit a rise in [Ca2+](i) that involves entry of calcium via L-type calcium channels. (C) 2008 Elsevier B.V. All rights reserved.