Kass R S, Scheuer T, Malloy K J
J Gen Physiol. 1982 Jun;79(6):1041-63. doi: 10.1085/jgp.79.6.1041.
We have studied the effects of iontophoretic injection of the quaternary ammonium compounds tetraethylammonium (TEA) and tetrabutylammonium (TBA) in cardiac purkinje fibers. We find that TBA(+) is a more effective blocker than TEA(+), but injection of either compound reduces the time-dependent outward plateau currents, transient outward current (I(to)), and the delayed rectifier (I(x)). Our findings provide evidence that these outward cardiac currents are carried by channels that in some respects are pharmacologically similar to squid axon potassium channels. We demonstrate that this procedure is a new tool that can be useful in the analysis of membrane currents in the heart.
我们研究了在心脏浦肯野纤维中离子电渗注入季铵化合物四乙铵（TEA）和四丁铵（TBA）的效果。我们发现TBA(+)比TEA(+)是更有效的阻滞剂，但注入这两种化合物中的任何一种都会减少时间依赖性外向平台电流、瞬时外向电流（I(to)）和延迟整流电流（I(x)）。我们的研究结果表明，这些心脏外向电流是由在某些方面在药理学上类似于鱿鱼轴突钾通道的通道所携带的。我们证明，该方法是一种可用于分析心脏膜电流的新工具。
