Senami M, Irisawa H
Jpn J Physiol. 1981;31(2):225-36. doi: 10.2170/jjphysiol.31.225.
Using small rabbit sino-atrial node preparations, the effects of procaine amide in concentrations from 0.01 to 2 mg/ml on the membrane potentials currents were studied by both current-clamp and voltage-clamp experiments. Procaine amide in concentrations over 0.1 mg/ml reduced the peak of the action potential, maximum diastolic potential and the maximum rate of depolarization. The action potential duration was prolonged, the resting potential was decreased and the heart rate was reduced. In the voltage-clamp experiments, procaine amide (0.1 mg/ml) reduced the slow inward current (is), the outward current (iK) and the inward current activated by hyperpolarization (ih). The major effect, however, was the reduction of the outward current. Sine the degree of the steady-state activation of iK and its time constant were unchanged, the observed reduction of iK could have been caused by a reduction of iK.
使用小型兔窦房结标本，通过电流钳和电压钳实验研究了浓度为0.01至2mg/ml的普鲁卡因胺对膜电位电流的影响。浓度超过0.1mg/ml的普鲁卡因胺降低了动作电位的峰值、最大舒张电位和最大去极化速率。动作电位持续时间延长，静息电位降低，心率减慢。在电压钳实验中，普鲁卡因胺（0.1mg/ml）降低了慢内向电流（is）、外向电流（iK）和超极化激活的内向电流（ih）。然而，主要作用是外向电流的降低。由于iK的稳态激活程度及其时间常数未改变，观察到的iK降低可能是由iK的减少引起的。
