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兔血管平滑肌延迟整流钾通道研究及其与克隆Kv1.5通道的电生理特性比较

徐文洪, 李婉, 王晓良

中国医学科学院中国协和医科大学药物研究所药理三室

摘要

本文用膜片箝全细胞技术比较研究了单个兔肺动脉血管平滑肌细胞上延迟整流钾通道与克隆Kv1．5通道的电生理及药理学特性。将平滑肌细胞箝制在-40mV，以10mV的步距阶跃去极化（0～60mV）可产生一系列快速上升的外向电流，几无衰减，其激活曲线的V1/2为27．2mV。灌流液中加入100mmol／LTEA和1mmol／L　4AP，电流幅度均明显减小，细胞外Ca2+水平由1．5mmol／L降至0．5mml／L甚至0mmol／L时，该电流无明显改变。而在HBK7细胞（克隆Kv1．5通道），箝制在－80mV，以10mV的步距阶跃去极化（－30～＋60mV），可产生一系列的快速上升的外向电流，激活更快，无衰减，其激活曲线的V1/2为0．8mV。4AP抑制Kv1．5的IC50为7．3mmol／L，呈现频率和使用非依赖性；TEA30，100，300mmol／L分别使该电流幅度下降28.6％，37.4％，46．3％，Quinidine0．1和1mmol／L使其下降29．7％，37．6％。研究表明，我们记录到急性分离的免血管平滑肌细胞延迟整流钾通道，它的电生理及药理学特性与克隆的Kv1．5延迟整流钾通道存在明显差别。

关键词： 血管平滑肌细胞; Kv1．5钾通道; 膜片箝全细胞记录; 延迟整流钾通道; 四乙胺; 4-氨基吡啶

MA Yong-Jie

2College of Information Engineering, Taishan Medical University, Taian 271016, China

Abstract

Whole cell patch-clamp recorrding techniques were used to compare the electrophysiological properties between deayed rectifier K+ current of rabbit vascular smooth muscle cell(VSMC)and the cloned Kvl.5 channel.When VSMC is clamped at -40 mV,depolarizing the membrane potential at increasing steps of 10 mV could evoke a series of outward potassium cmrrents without any deactivation.The V1/2 of the activation curve was 27.2 mV.The curmnts decrease obviously after adding 100 mmol/L TEA or 1 mmol/L 4AP in the perfusate.When the concentration of extracellular Ca2+ was decreased from 1.5 mmol/L to 0.5 or 0 mmol/L,the currents did not show much change,while in HBK7(cloned Kv1.5 channel cell)held at-8O mV,similar steparise depolarizaton could also produce a series of outward potassium currents without any deactivation decayed.V1/2 of the activation was 0.8 mV.4AP inhibited the cloned channel current with IC50 of 7.3 mmol/L,showing neither frequency-or use-dependence.

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引用本文：

徐文洪, 李婉, 王晓良. 兔血管平滑肌延迟整流钾通道研究及其与克隆Kv1.5通道的电生理特性比较[J]. 生理学报 1998; 50 (1): .

MA Yong-Jie. . Acta Physiol Sin 1998; 50 (1): (in Chinese with English abstract).