第 4 期 - 静息膜电位
中文名称
通路描述
第 4 期描述了细胞未被刺激时的膜电位。心室心肌的正常静息电位介于 -85 至 -95 mV 之间。由于细胞膜对 K+ 最通透，对其他离子相对不通透，因此细胞膜两侧的 K+ 梯度是正常静息电位的决定性因素（Park & Fishman 2011, Grant 2009）。在此阶段，K+ 电流由内向整流钾通道（KCNJs）和串联孔域钾通道（KCNKs）产生。某些 Na+/K+-ATP 酶和 Na+/Ca2+-交换器也能在此阶段发挥作用。
英文描述
Phase 4 - resting membrane potential Phase 4 describes the membrane potential when a cell is not being stimulated. The normal resting potential in the ventricular myocardium is between -85 to -95 mV. The membrane is most permeable to K+ and relatively impermeable to other ions therefore the K+ gradient across the cell membrane is the key determinant in the normal resting potential (Park & Fishman 2011, Grant 2009). In this phase, K+ currents are generated by inward rectifier potassium channels (KCNJs) and tandem pore domain K+ channels (KCNKs). Some Na+/K+-ATPases and Na+/Ca2+-exchangers can also play roles during this phase.
所含基因
19 个基因