COMPARATIVE ASPECTS OF IONIC CONDUCTANCES IN NERVE AND HEART CELL MEMBRANES

神经细胞和心脏细胞膜中离子电导的比较

• 批准号: 3922558
• 负责人: J R CLAY
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3922558
• 关键词: Cephalopoda; adenosine triphosphate; arrhythmia; axon; cell membrane; chick embryo; electrophysiology; embryo /fetus cell /tissue; extracellular; heart cell; ion transport; membrane channels; membrane permeability; membrane potentials; membrane transport proteins; microelectrodes; neural conduction; neurophysiology; phosphorylation; saltwater environment; single cell analysis; transport proteins

This project is concerned with a comparative analysis of ionic current channels in nerve and heart cell membranes and the relationship of these channels to electrical excitability, with a Particular emphasis on potassium ion channels in both preparations and the effects of various ionic blockers on these channels. During the past year the primary experimental preparations which have been used are squid giant axons and chick embryonic heart cells. This work has focused recently on the delayed rectifier potassium channel, IK, in squid axons. A major finding has been that this channel is modulated by the intracellular application of adenosine triphosphate (ATP). Specifically, the voltage dependence of the inactivation of IK is shifted in the hyperpolarizing direction by ATP, which suggest that the basal ATP level regulates excitability of the squid axon at rest. The effect is probably mediated by phosphorylation of a subunit of the membrane protein which comprises the IK channel, which suggests that the channel protein, or part of the channel protein, may be amenable to isolation and purification by biochemical techniques.

该项目涉及离子的比较分析， 神经和心脏细胞膜中的电流通道， 这些通道与电兴奋性的关系， 两种制剂均特别强调钾离子通道 以及各种离子阻断剂对这些通道的影响。 在过去的一年里， 已经被使用的是鱿鱼的巨大轴突和鸡胚心脏 细胞 这项工作最近集中在延迟整流器 钾离子通道，IK，在鱿鱼轴突。 一个主要的发现是 这个通道是由细胞内的 三磷酸腺苷（ATP）。 具体来说，电压依赖性 IK的失活在超极化过程中发生了变化， 这表明基础ATP水平调节 鱿鱼轴突在休息时的兴奋性 其影响可能是 由膜蛋白亚基磷酸化介导 它包括IK通道，这表明通道 蛋白质或通道蛋白的一部分可以服从于 通过生物化学技术分离和纯化。