Nonselective suppression of voltage-gated currents by odorants in the newt olfactory receptor cells.
Nonselective suppression of voltage-gated currents by odorants in the newt olfactory receptor cells.
复制标题
DOI：
10.1085/jgp.109.2.265
复制
发表时间：
1997-02
期刊：
影响因子：
--
通讯作者：
Kaneko A
中科院分区：
文献类型：
--
作者：
Kawai F;Kurahashi T;Kaneko A
采用全细胞膜片钳技术研究了气味物质对蝾螈嗅觉受体细胞电压门控离子通道的影响。在电压钳下，膜从−100 mV的保持电位（Vh）去极化到−90 mV和+40 mV之间的电压产生了时间和电压依赖性电流反应;一个快速（< 15 ms）衰减的初始内向电流和一个晚期外向电流。当将气味剂（1 mM乙酸戊酯、1 mM苯乙酮和1 mM柠檬烯）应用于记录的细胞时，电压门控电流显著降低。乙酸戊酯对各电流成分（Na+电流：INa，T-型Ca ~（2+）电流：伊卡，T，L-型Ca ~（2+）电流：伊卡，L，延迟整流K ~+电流：IKv和Ca ~（2+）激活K ~+电流：IK（Ca））的剂量-抑制关系可用Hill方程拟合。每个电流的半阻断浓度为0.11 mM（INa）、0.15 mM（伊卡，T）、0.14 mM（伊卡，L）、1.7 mM（IKv）和0.17 mM（IK（Ca）），希尔系数为1.4（INa）、1.0（伊卡，T）、1.1（伊卡，L）、1.0（IKv）和1.1（IK（Ca））。这表明内向电流比外向电流受到更强的影响。乙酸戊酯对INa的激活曲线无明显影响，但使其失活曲线向负电压方向移动;对照组的半激活电压为−53 mV，0.01 mM时为−66 mV，0.1 mM时为−84 mV。这些现象与局部麻醉剂的抑制作用相似（利多卡因和苯并咪唑）对INa在各种制剂，这表明这两种类型的抑制是由相同的机制。这里观察到的离子通道的非选择性阻断与先前的观点一致，即气味剂对转导电流的抑制是由于转导通道的直接阻断。
Effects of odorants on voltage-gated ionic channels were investigated in isolated newt olfactory receptor cells by using the whole cell version of the patch–clamp technique. Under voltage clamp, membrane depolarization to voltages between −90 mV and +40 mV from a holding potential (Vh) of −100 mV generated time- and voltage-dependent current responses; a rapidly (< 15 ms) decaying initial inward current and a late outward current. When odorants (1 mM amyl acetate, 1 mM acetophenone, and 1 mM limonene) were applied to the recorded cell, the voltage-gated currents were significantly reduced. The dose-suppression relations of amyl acetate for individual current components (Na+ current: INa, T-type Ca2+ current: ICa,T, L-type Ca2+ current: ICa,L, delayed rectifier K+ current: IKv and Ca2+-activated K+ current: IK(Ca)) could be fitted by the Hill equation. Half-blocking concentrations for each current were 0.11 mM (INa), 0.15 mM (ICa,T), 0.14 mM (ICa,L), 1.7 mM (IKv), and 0.17 mM (IK(Ca)), and Hill coefficient was 1.4 (INa), 1.0 (ICa,T), 1.1 (ICa,L), 1.0 (IKv), and 1.1 (IK(Ca)), suggesting that the inward current is affected more strongly than the outward current. The activation curve of INa was not changed significantly by amyl acetate, while the inactivation curve was shifted to negative voltages; half-activation voltages were −53 mV at control, −66 mV at 0.01 mM, and −84 mV at 0.1 mM. These phenomena are similar to the suppressive effects of local anesthetics (lidocaine and benzocaine) on INa in various preparations, suggesting that both types of suppression are caused by the same mechanism. The nonselective blockage of ionic channels observed here is consistent with the previous notion that the suppression of the transduction current by odorants is due to the direst blockage of transduction channels.
登录
查看更多内容
DOI：
10.1085/jgp.90.1.95
发表时间：
1987-07
期刊：
The Journal of general physiology
影响因子：
--
作者：
Maue RA;Dionne VE
通讯作者：
Dionne VE
影响因子：
5.7
作者：
Breer, H;Boekhoff, I
通讯作者：
Boekhoff, I
影响因子：
7.3
作者：
AKAIKE, N;ITO, H;OYAMA, Y
通讯作者：
OYAMA, Y
DOI：
10.1085/jgp.103.2.181
发表时间：
1994-02
期刊：
The Journal of general physiology
影响因子：
--
作者：
Dubin AE;Dionne VE
通讯作者：
Dionne VE
影响因子：
5.5
作者：
ALMERS, W
通讯作者：
ALMERS, W