VOLTAGE GATED CARDIAC POTASSIUM CHANNELS

电压门控心脏钾通道

• 批准号: 3366819
• 负责人: DIRK J SNYDERS
• 金额: $ 12.98万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-01 至 1996-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3366819
• 关键词: CHO cells; L cell; animal tissue; antiarrhythmic agent; electrophysiology; heart cell; heart pharmacology; human tissue; mathematical model; molecular cloning; phenotype; phosphorylation; potassium channel; voltage /patch clamp; voltage gated channel

The long-term objective of my research is to study ion channel function and its relation to excitability, particularly in cardiac cells. In this work, I use a range of techniques and preparations. The current proposal is aimed at studying cardiac potassium channels in a newly developed system in which cloned channels are expressed. An expression system will be especially valuable because the study of cardiac K channels in native cells presents a series of technical difficulties. First the presence of more than ten potassium channels with diverse physiologies complicates detailed analysis of any individual potassium channel. Second, some are observed in less than 1/100 patches preventing reliable single channel analysis. Recent advances in molecular biology now provide unprecedented opportunities to clone and express individual channels. At Vanderbilt, seven potassium channels have been cloned from rat and human heart. These have been expressed in Xenopus oocytes but processing of such expressed channels may be different in mammalian cells. More recently, stable expression has been achieved in a mammalian cell line, mouse L-cells. The aims of this research project are to study physiological and pharmacological properties of cardiac potassium channels expressed individually in this new system, and to relate to results to channel function in native cells. The advantages of this expression system will be exploited to study in detail the voltage- and state-dependent interaction of drugs with these channels. Voltage clamp techniques, including whole cells, single channel and macropatch, will be used to analyze ion transfer, ion selectivity, gating properties, and drug sensitivity of these channels. Mathematical modelling will be used to provide a framework for further analyzing the experimental data, and to guide additional experiments. The properties of expressed channels win be compared to those of native channels further develop an understanding of the components which contribute to overall K current in cardiac cells. Potassium channels play an important role in controlling cardiac excitability and repolarization, and are the target for many available and investigational ('class III') antiarrhythmic agents. The information gained from this project will expand our knowledge of the function of these important channels, which may ultimately result in improved understanding of the mechanisms of arrhythmias and in the development of better antiarrhythmic drugs.

我研究的长期目标是研究离子通道功能 及其与兴奋性的关系，特别是心肌细胞的兴奋性。 在这个 在工作中，我使用了一系列的技巧和准备工作。 目前的提案 旨在研究新开发的心脏钾通道 表达克隆通道的系统。 表达系统将 尤其有价值，因为对本地人心脏 K 通道的研究 细胞存在一系列技术困难。 首先存在 十多个具有不同生理功能的钾通道使情况变得复杂 任何单个钾通道的详细分析。 其次，有些是 在不到 1/100 的斑块中观察到，妨碍了可靠的单通道 分析。 分子生物学的最新进展现在提供了前所未有的 克隆和表达个人渠道的机会。 在范德比尔特， 已从大鼠和人类心脏中克隆出七个钾通道。 这些已在非洲爪蟾卵母细胞中表达，但此类的加工 哺乳动物细胞中的表达通道可能不同。 最近， 已在哺乳动物细胞系、小鼠中实现稳定表达 L细胞。 该研究项目的目的是研究生理学 表达的心脏钾通道和药理特性 单独在这个新系统中，并将结果与​​渠道联系起来 在天然细胞中发挥作用。 该表达系统的优点将 用于详细研究电压和状态相关的 药物与这些通道的相互作用。 电压钳技术， 包括全细胞、单通道和宏贴片，将用于 分析离子转移、离子选择性、门控特性和药物 这些通道的灵敏度。 数学建模将用于 提供进一步分析实验数据的框架 指导额外的实验。 表达渠道的属性获胜 与原生渠道进行比较，进一步加深理解 影响心肌细胞总 K 电流的成分。 钾通道在控制心脏功能中发挥着重要作用 兴奋性和复极化，是许多可用的目标 和研究性（“III 类”）抗心律失常药物。 信息 从这个项目中获得的知识将扩展我们对功能的了解 这些重要的渠道，最终可能会导致改善 了解心律失常的机制和发展 更好的抗心律失常药物。