Ochi R
Department of Physiology, Juntendo University School of Medicine.
Nihon Rinsho. 1993 May;51(5):1140-5.
The paper summarizes the recent progress of research on the structure, function and regulation of cardiac ion channels. The primary structures of voltage-gated Na and Ca channels are homologous, with identical voltage sensors and homologous pore structure. The voltage-gated channels are modulated by sympathetic and vagal transmitters. beta-Stimulants phosphorylate various channels by activating cyclic AMP-dependent kinase, while acetylcholine antagonizes this phosphorylation. The phosphorylation inhibits the Na current by promoting inactivation, increases the L-type Ca current by increasing the channel availability, increases the delayed rectifying K current and induces Cl current. Acetylcholine induces a K current in nodal and atrial cells via a direct binding of beta gamma subunit of GTP-binding protein (GK) to the K channel.
本文总结了心脏离子通道结构、功能及调节方面的最新研究进展。电压门控钠通道和钙通道的一级结构具有同源性，具有相同的电压感受器和同源的孔道结构。电压门控通道受交感和迷走神经递质调节。β激动剂通过激活环磷酸腺苷依赖性激酶使各种通道磷酸化，而乙酰胆碱则拮抗这种磷酸化作用。磷酸化通过促进失活来抑制钠电流，通过增加通道的可利用性来增加L型钙电流，增加延迟整流钾电流并诱导氯电流。乙酰胆碱通过GTP结合蛋白（GK）的βγ亚基与钾通道直接结合，在窦房结和心房细胞中诱导钾电流。
