Wakui M, Inomata H
Jpn J Physiol. 1984;34(1):199-203. doi: 10.2170/jjphysiol.34.199.
Noradrenaline (NA) evoked a contraction which consisted of two components, an initial one associated with only depolarization and a second one with spike discharges. Both contractions were abolished in a Ca-free solution leaving only small depolarization. In a Na-free solution, the initial contraction was increased in keeping with the short term depolarization, while the second contraction was abolished. It is suggested that NA initially causes Ca influx which secondarily increases Na permeability.
去甲肾上腺素（NA）引发了一种收缩，该收缩由两个部分组成，一个初始部分仅与去极化相关，另一个部分与动作电位发放相关。在无钙溶液中，两种收缩均被消除，仅留下小的去极化。在无钠溶液中，初始收缩随着短期去极化而增强，而第二种收缩被消除。提示NA最初引起钙内流，继而增加钠通透性。
