A caffeine- and ryanodine-sensitive Ca2+ store in avian sensory neurons.
A caffeine- and ryanodine-sensitive Ca2+ store in avian sensory neurons.
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DOI：
10.1152/jn.1993.70.2.710
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发表时间：
1993-08
影响因子：
2.5
通讯作者：
A. Ivanenko;M. Baring;J. Airey;J. Sutko;J. L. Kenyon
中科院分区：
文献类型：
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作者：
A. Ivanenko;M. Baring;J. Airey;J. Sutko;J. L. Kenyon
1.本实验对鸡胚背根神经节（DRG）神经元的兰尼碱受体进行了鉴定和功能研究。2.一种单克隆抗体（mAb 34 C），识别所有已知的骨骼肌和心肌和中枢神经系统中的兰尼碱受体亚型确定培养的DRG神经元中的兰尼碱受体样免疫反应性。3.用透性膜片技术记录膜电流，我们发现在大约三分之二的神经元中，钙电流之后是具有Ca（2+）激活的Cl-电流（ICl（Ca））特征的电流。在这些细胞中，急性应用10 mM咖啡因激活了类似的ICl（Ca），这种作用被10 μ M ryanodine抑制。咖啡因对ICl（Ca）的激活不依赖于细胞外Ca ~（2+）。这些数据表明，咖啡因提高细胞内游离Ca 2+（Cai 2+），激活释放的Ca 2+从细胞内存储，这种Ca 2+激活负责ICl（Ca）的膜电导。4.由去极化激活的ICl（Ca）的幅度不受ryanodine的影响，这意味着在该方案中激活ICl（Ca）的Ca 2+由Ca 2+电流提供，而没有通过ryanodine敏感机制（例如Ca（2+）诱导的Ca 2+释放）放大。5.我们还使用indo-1来测量DRG神经元中的Cai 2+。10毫摩尔咖啡因引起Cai 2+的短暂增加，10 μ M ryanodine抑制Cai 2+。6.咖啡因升高Cai 2+和激活ICl（Ca）的能力在较高温度下降低，表明增加Ca 2+螯合。7.这些数据表明，存在的细胞内存储的Ca 2+，可以动员的咖啡因和ryanodine敏感的机制。Ca ~（2+）的释放可以升高Ca ~（2+）并调节膜电导。
1. We identified and studied the function of ryanodine receptors in neurons isolated from dorsal root ganglia (DRG) of 10-day-old chick embryos. 2. A monoclonal antibody (mAb 34C) that recognizes all known ryanodine receptor isoforms in skeletal and cardiac muscle and CNS identified ryanodine receptor-like immunoreactivity in cultured DRG neurons. 3. Using the permeabilized patch technique to record membrane currents, we found that calcium currents were followed by a current with characteristics of a Ca(2+)-activated Cl- current (ICl(Ca)) in approximately two-thirds of the neurons. In these cells, acute application of 10 mM caffeine activated a similar ICl(Ca) and this effect was inhibited by 10 microM ryanodine. The activation of ICl(Ca) by caffeine was not dependent on extracellular Ca2+. These data suggest that caffeine raises intracellular free Ca2+ (Cai2+) by activating the release of Ca2+ from an intracellular store and that this Ca2+ activates the membrane conductance responsible for ICl(Ca). 4. The magnitude of ICl(Ca) activated by depolarization was not affected by ryanodine, implying that the Ca2+ that activates ICl(Ca) in this protocol is supplied by the Ca2+ current without amplification by a ryanodine-sensitive mechanism such as Ca(2+)-induced Ca2+ release. 5. We also used indo-1 to measure Cai2+ in DRG neurons. Ten millimolar caffeine caused a transient increase in Cai2+ that was inhibited by 10 microM ryanodine. 6. The ability of caffeine to elevate Cai2+ and activate ICl(Ca) was reduced at higher temperatures, suggesting increased Ca2+ sequestration. 7. These data demonstrate the existence of an intracellular store of Ca2+ that can be mobilized by a caffeine- and ryanodine-sensitive mechanism. The release of Ca2+ from this store can elevate Cai2+ and modulate membrane conductances.