EXTRACELLULAR ATP ELEVATES CYTOSOLIC CA2+ IN COCHLEAR INNER HAIR-CELLS
EXTRACELLULAR ATP ELEVATES CYTOSOLIC CA2+ IN COCHLEAR INNER HAIR-CELLS
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DOI：
10.1097/00001756-199102000-00001
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发表时间：
1991-02-01
期刊：
影响因子：
1.7
通讯作者：
ARAN, JM
中科院分区：
文献类型：
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作者：
DULON, D;MOLLARD, P;ARAN, JM
ATP对离体感觉内毛细胞（IHC）的局部细胞外应用产生胞质游离Ca 2+浓度的快速和短暂的增加，在1至5秒内达到峰值。 剂量-反应曲线表明半最大刺激为5 μ M ATP。 ADP和α-β-亚甲基ATP的结构衍生物的应用没有产生显著的Ca 2+响应。 相比之下，ATP-α-S，P2 z受体的激动剂，在产生Ca 2+反应中是完全活性的。 在细胞外游离钙缺乏的情况下，仍然观察到ATP诱导的Ca 2+增加，表明ATP产生了从内部储存的Ca 2+的释放。 这些结果表明，细胞外ATP，通过激活P2-嘌呤能受体，可能有神经调节作用的耳蜗生理水平的IHC。
THE local extracellular application of ATP to isolated sensory inner hair cells (IHC) generated a rapid and transient increase in the concentration of cytosolic free Ca2+, peaking within 1 to 5 s. The dose-response curve indicated a half-max stimulation to be 5 mu-M ATP. The application of the structural derivatives ADP and alpha-beta-methyleneATP did not generate significant Ca2+ response. By contrast, ATP-alpha-S, an agonist for P2z receptor, was fully active in generating Ca2+ responses. In the absence of extracellular free calcium, the ATP-induced Ca2+ increase was still observed, indicating that ATP generated the liberation of Ca2+ from internal stores. These results suggest that extracellular ATP, through an activation of P2-purinergic receptors, may have a neuromodulatory role in the cochlear physiology at the level of the IHC.