Ca2+ dynamics in the lumen of the endoplasmic reticulum in sensory neurons:: direct visualization of Ca2+-induced Ca2+ release triggered by physiological Ca2+ entry
Ca2+ dynamics in the lumen of the endoplasmic reticulum in sensory neurons:: direct visualization of Ca2+-induced Ca2+ release triggered by physiological Ca2+ entry
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DOI：
10.1093/emboj/21.4.622
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发表时间：
2002-02-15
期刊：
影响因子：
11.4
通讯作者：
Verkhratsky, A
中科院分区：
文献类型：
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作者：
Solovyova, N;Veselovsky, N;Verkhratsky, A
在培养的大鼠背根神经节神经元上，我们用膜片钳全细胞技术测量了膜电流，并用高(Fluo-3)和低(Mag-Fura-2)亲和力钙敏感的荧光探针和视频成像技术测量了胞浆([Ca~(2+)](I))和内质网(ER)([Ca~(2+)](L))内的游离钙离子浓度。静息[Ca~(2+)](L)浓度在60~270微米之间变化。咖啡因激活兰尼定受体后，细胞内[Ca~(2+)](L)水平迅速下降，仅为静息状态[Ca~(2+)](L)的40-50%。利用电生理去极化技术，我们直接演示了钙离子通过电压门控钙通道内流触发钙离子释放的过程。内质网内膜钙释放的幅度与钙离子浓度呈线性关系。
In cultured rat dorsal root ganglia neurons, we measured membrane currents, using the patch-clamp whole-cell technique, and the concentrations of free Ca2+ in the cytosol ([Ca2+](i)) and in the lumen of the endoplasmic reticulum (ER) ([Ca2+](L)), using high- (Fluo-3) and low- (Mag-Fura-2) affinity Ca2+-sensitive fluorescent probes and video imaging. Resting [Ca2+](L) concentration varied between 60 and 270 muM. Activation of ryanodine receptors by caffeine triggered a rapid fall in [Ca2+](L) levels, which amounted to only 40-50% of the resting [Ca2+](L) value. Using electrophysiological depolarization, we directly demonstrate the process of Ca2+-induced Ca2+ release triggered by Ca2+ entry through voltage-gated Ca2+ channels. The amplitude of Ca2+ release from the ER lumen was linearly dependent on I-Ca.