Calmodulin antagonists do note inhibit IKCa channels of human erythrocytes
Calmodulin antagonists do note inhibit IKCa channels of human erythrocytes
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DOI：
10.1016/s0005-2736(01)00419-9
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发表时间：
2002-02-01
影响因子：
3.4
通讯作者：
Pellegrino, M
中科院分区：
文献类型：
--
作者：
Del Carlo, B;Pellegrini, M;Pellegrino, M
应用膜片钳技术研究了三种钙调素（CaM）拮抗剂对人红细胞中间型钙激活钾通道（IKCa）门控的影响。在细胞贴壁构型中，对照细胞与钙咪唑、三氟拉嗪或W7孵育的细胞IKCa通道的开放频率和开放概率无显著差异。在离体膜斑中的IKCa通道，在钙离子浓度范围为10（-7）至10（-3）M的CaM拮抗剂存在下，通常被胞质侧的钙离子所激活。IKCa通道的活性，这是以前上调内源性cAMP依赖性蛋白激酶，灌注钙调素拮抗剂时，没有受到抑制。本研究的结果表明，钙调素拮抗剂不抑制人红细胞天然IKCa通道的活性。这些数据是根据克隆IKCa的研究结果表明，钙调蛋白是组成性与这些通道。(C)2002 Elsevier Science B. V.保留所有权利。
Patch-clamp recordings were performed to study the effects of three calmodulin (CaM) antagonists on the gating of intermediate calcium-activated K+ channels (IKCa) of human erythrocytes In the cell-attached configuration, both opening frequency and open probability of IKCa channels were not significantly different in control cells and in those incubated with calmidazolium, trifluoperazine or W7. IKCa channels in excised membrane patches, were normally activated by the calcium bathing the cytoplasmic side in the presence of CaM antagonists, at calcium concentrations ranging from 10(-7) to 10(-3) M. The activity of IKCa channels, which had been previously up-modulated by an endogenous cAMP-dependent protein kinase, was not inhibited when perfused with CaM antagonists. The results presented in this study demonstrate that calmodulin antagonists do not inhibit the activity of native IKCa channels of human erythrocytes. These data are in accordance with findings on the cloned IKCa indicating that calmodulin is constitutively associated with these channels. (C) 2002 Elsevier Science B.V. All rights reserved.