Pharmacology of the human red cell voltage-dependent cation channel. Part II: inactivation and blocking
Pharmacology of the human red cell voltage-dependent cation channel. Part II: inactivation and blocking
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DOI：
10.1016/j.bcmd.2004.07.001
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发表时间：
2004-11-01
影响因子：
2.3
通讯作者：
Christophersen, P
中科院分区：
文献类型：
--
作者：
Bennekou, P;Barksmann, TL;Christophersen, P
研究了人红细胞非选择性电压依赖性阳离子通道(NSVDC)的药理调节作用。使用无机阳离子Ru红和La3+，以及有机硫基试剂碘乙酰胺(IAA)和N-乙基马来酰亚胺(NEM)，可以表现出电压激活电导的浓度依赖性降低，反映了通道的抑制或失活。初始电压激活是通过向低氯浓度的蔗糖取代的Ringers中注入人红细胞来实现的，这导致了膜电位的强正性，最初由Cl-的平衡电位(接近+100 mV)决定。由于阳离子通道的电压和时间依赖性的激活，出现了通过添加氯离子电导阻滞剂而最小化的净流出，V-m逐渐减小并稳定在比E-Cl更小的正值，反映了阳离子电导g(+)的增加，达到1.5-2.0mus/cm(2)。在NSVDC通道阻滞剂的存在下，膜电位复极和阳离子外流均被抑制。(C)2004 Elsevier Inc.保留所有权利。
Pharmacological modulation of the nonselective voltage-dependent cation (NSVDC) channel from human erythrocytes was studied. Using the inorganic cations ruthenium red and La3+, as well as the organic thiol group reagents iodoacetamide (IAA) and N-ethylmaleimide (NEM), it was possible to demonstrate a concentration-dependent decrease in the voltage-activated conductance, reflecting an inhibition or inactivation of the channel. Initial voltage activation was achieved by injecting human red cells into sucrose-substituted Ringers with a low chloride concentration, which causes a strongly positive membrane potential to develop, initially determined by the equilibrium potential for Cl- (approximate to +100 mV). Due to the voltage- and time-dependent activation of the cation channel, net effluxes, minimized by addition of a chloride conductance blocker, occurred and V-m gradually decreased and stabilized at a value less positive than E-Cl, reflecting the increased cation conductance, g(+), reaching 1.5-2.0 muS/cm(2). In the presence of inhibitors of the NSVDC channel, both the membrane potential repolarization and the cation efflux were diminished. (C) 2004 Elsevier Inc. All rights reserved.