Jaeger J M, Gibbons W R
Am J Physiol. 1985 Jul;249(1 Pt 2):H108-21. doi: 10.1152/ajpheart.1985.249.1.H108.
Two outward currents, IX1 and IX2, are thought to be activated by depolarization of the Purkinje fiber. One of these, IX1, is presently believed to play a critical role in repolarization of the action potential. The IX currents were originally analyzed in voltage-clamp experiments in sheep Purkinje fibers. These experiments were designed to minimize interference by other currents, and it was assumed that changes of the net current were produced entirely by the IX currents. We have tried to repeat the original experiments and the analysis that led to acceptance of the existence and roles of the IX currents, without success. Moreover, tests of how membrane current should behave if the IX current hypothesis is correct did not give satisfactory results. Our data suggest the original conclusions about IX1 and IX2 may need substantial revision.
两种外向电流IX1和IX2被认为是由浦肯野纤维的去极化激活的。其中之一IX1，目前被认为在动作电位的复极化中起关键作用。IX电流最初是在绵羊浦肯野纤维的电压钳实验中进行分析的。这些实验旨在尽量减少其他电流的干扰，并假设净电流的变化完全由IX电流产生。我们试图重复最初的实验以及导致IX电流的存在和作用被认可的分析，但未成功。此外，如果IX电流假说是正确的，关于膜电流应如何表现的测试也未得到满意结果。我们的数据表明，关于IX1和IX2的最初结论可能需要大幅修正。
