Suppression and recovery of voltage-gated currents after cocaine treatments of olfactory receptor cells
Suppression and recovery of voltage-gated currents after cocaine treatments of olfactory receptor cells
复制标题
可卡因处理嗅觉受体细胞后电压门控电流的抑制和恢复
DOI：
10.1016/j.anl.2011.11.002
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发表时间：
2012
影响因子：
1.7
通讯作者：
Yamamoto T
中科院分区：
文献类型：
--
作者：
Tamari K;Takeuchi H;Kobayashi M;Kurahashi T;Yamamoto T
目的1-5%浓度的可卡因是鼻腔耳鼻咽喉手术常用的局麻药。最近的报告表明，一些患者抱怨手术后嗅觉障碍，可卡因滥用者的嗅觉下降。尽管有这些报道，但可卡因对嗅觉感受器细胞的影响尚不清楚。在全细胞记录结构的电压钳下，当膜电位从−100 mV在−90 mV到+40 mV之间逐级去极化时，记录到电压门控电流。结果当可卡因通过喷雾压力(5%)和细胞外溶液施加时，电压门控电流(包括内向和外向成分)显著减少。可卡因对钠电流和钾电流的剂量抑制曲线均可用Hill方程拟合。钠电流和钾电流的半阻断浓度分别为43μM和557μM，希尔系数分别为1.1和0.9。这一事实表明，外科手术中鼻腔局部大剂量治疗后，可卡因不会影响嗅觉能力。
OBJECTIVECocaine (1–5% concentrations) is commonly used as a local anesthetic for the otorhinolaryngeal surgery of the nasal cavity. Recent reports indicate that some patients complain of olfactory deficits after surgery, and decreased olfaction is found in cocaine abusers. In spite of these reports, the effects of cocaine on the olfactory receptor cells are unknown.METHODSEffect of cocaine was examined in olfactory receptor cells isolated from the newt. Under the voltage clamp with the whole-cell recording configuration, the voltage-gated currents were recorded when the membrane potential was depolarized from a holding potential of −100mV in a step wise between −90mV and +40mV.RESULTSWhen cocaine was applied by a puff pressure (5%) and the extracellular solution, the voltage-gated currents, including inward and outward components, were significantly reduced. The dose–suppression curves of cocaine for sodium and potassium currents could be fitted by the Hill equation. Half-blocking concentration of sodium and potassium currents were 43μM and 557μM; Hill coefficient was 1.1 and 0.9, respectively.CONCLUSIONThis rapid and complete recovery from the suppression was confirmed even after the treatments with the high concentration cocaine. This fact implies that cocaine does not affect olfactory ability after locally high dose treatments of nasal cavity in surgical operation.