Chlorpromazine alters outer hair cell electromotility
Chlorpromazine alters outer hair cell electromotility
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DOI：
10.1067/mhn.2001.116446
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发表时间：
2001-07-01
影响因子：
3.4
通讯作者：
Brownell, WE
中科院分区：
文献类型：
--
作者：
Lue, AJC;Zhao, HB;Brownell, WE
目的：内耳外毛细胞将电梯度快速转化为机械力，增强耳蜗的灵敏度和频率选择性。我们研究氯丙嗪对OHC电动力的影响，氯丙嗪是一种改变膜生物力学的抗精神病药物。研究设计：在全细胞膜片移液管记录条件下，用氯丙嗪灌注离体豚鼠外毛细胞。测量了电运动反应。结果：在氯丙嗪处理下，出现了显著的、可逆的、剂量依赖性的峰值电容电压去极化（V-pkCm）。在施用氯丙嗪前后，V-pkCm附近的电响应增益最大。与其他3种改变电动力的药物（水杨酸盐、镧系元素、膜张力）不同，氯丙嗪不改变峰值电容（Cm-pk），其与最大电动力增益直接相关。结论：氯丙嗪改变了OHCs表现出最大电动力增益时的膜电压，而不改变电动力响应的大小。意义：大剂量氯丙嗪可降低听力阈值或耳声发射。
OBJECTIVE: Outer hair cells (OHCs) of the inner ear rapidly convert electrical gradients into mechanical force, enhancing cochlear sensitivity and frequency selectivity. We investigated the effect of chlorpromazine, an antipsychotic medication that alters membrane biomechanics, on OHC electromotility.STUDY DESIGN: Isolated guinea pig outer hair cells were perfused with chlorpromazine under whole-cell patch-pipette recording conditions. Electromotile responses were measured.RESULTS: A dramatic, reversible, dose-dependent depolarization of voltage at peak capacitance (V-pkCm) was seen with chlorpromazine treatment. The gain of the electromotile response was maximal near V-pkCm both before and after chlorpromazine application. Unlike the 3 other agents that alter electromotility (salicylate, lanthanides, membrane tension), chlorpromazine did not change peak capacitance (Cm-pk), which varies directly with maximal electromotile gain.CONCLUSION: Chlorpromazine changes the membrane voltage at which OHCs exhibit maximal electromotile gain, without changing the magnitude of electromotile responses.SIGNIFICANCE: Chlorpromazine may diminish hearing thresholds or otoacoustic emissions in large doses.