Kass R S
Biophys J. 1984 Apr;45(4):837-9. doi: 10.1016/S0006-3495(84)84227-7.
This study was designed to test the hypothesis that an outward current (Ix) responsible for action potential repolarization in the cardiac Purkinje fiber is activated by intracellular calcium (Cai). Pharmacological probes were combined with the measurement of membrane current and contractile activity under voltage clamp conditions. Experiments were designed to examine properties of Ix that have previously linked activation of this current to changes in Cai. The independence of Ix from Cai was demonstrated for each case tested. Thus, the results of these experiments support the view that Ix is not a calcium-activated current.
本研究旨在验证一个假设,即负责心脏浦肯野纤维动作电位复极化的外向电流(Ix)由细胞内钙(Cai)激活。在电压钳制条件下,将药理学探针与膜电流和收缩活性的测量相结合。实验旨在研究Ix的特性,此前已有研究将该电流的激活与Cai的变化联系起来。在每个测试案例中,均证明了Ix与Cai无关。因此,这些实验结果支持了Ix不是钙激活电流这一观点。