The human red cell voltage-dependent cation channel. Part III: Distribution homogeneity and pH dependence
The human red cell voltage-dependent cation channel. Part III: Distribution homogeneity and pH dependence
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DOI：
10.1016/j.bcmd.2005.10.004
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发表时间：
2006-01-01
影响因子：
2.3
通讯作者：
Kristensen, BI
中科院分区：
文献类型：
--
作者：
Bennekou, P;Barksmann, TL;Kristensen, BI
本文研究了非选择性电压依赖性阳离子通道(NSVDC通道)在人红细胞内分布的均质性和pH依赖性。该通道的激活引起细胞的均匀脱水，表现为红细胞渗透阻力谱的变化：激活1/2小时后，50%溶血时的渗透压由73 mM(对照)变为34 mM，分别相当于0.48%和0.21%的氯化钠。不变的标准差表示整个红细胞群体的参与，这意味着NSVDC通道在细胞中均匀分布。用N-乙基马来酰亚胺(NEM)灭活NSVDC通道或用NS1652阻断氯离子电导可延缓阻力谱向低渗透压的迁移。NSVDC通道的激活被细胞内pH的降低所阻断，但不被细胞外pH的降低所阻断。该效应的表观pK(A)值估计为6.5，特异性组氨酸试剂2.4‘-二溴苯乙酮(DBAB)使NSVDC通道失活。(C)2005 Elsevier Inc.保留所有权利。
The homogeneity of the distribution of the non-selective voltage-dependent cation channel (the NSVDC channel) in the human erythrocyte, and the pH dependence was investigated. Activation of this channel caused a uniform cellular dehydration, which was characterized by the changes in the erythrocyte osmotic resistance profiles: After 1/2 h of activation, the osmolarity at 50% hemolysis changed from 73 mM (control) to 34 mM NaCl, corresponding to 0.48% and 0.21% NaCl respectively. Unchanging standard deviations show participation of the entire erythrocyte population, which implies an even distribution of the NSVDC channel among the cells. Inactivation of the NSVDC channel with N-ethyl-maleimide (NEM) or blocking of the Cl- conductance with NS1652 retarded the migration of the resistance profiles towards lower osmolarities. The NSVDC channel activation was blocked by a decrease of the intracellular - but not the extracellular - pH. The apparent pK(A) value for the effect was estimated to be 6.5, and the specific histidine reagent 2.4'-dibromoacetophenone (DBAB) inactivated the NSVDC channel. (c) 2005 Elsevier Inc. All rights reserved.