Pan H, Shen W Q, Yu Z M, Xu B
Department of Physiology, Suzhou Medical College, China.
Zhongguo Yao Li Xue Bao. 1990 Jul;11(4):317-21.
Changrolin (CRL) is a new antiarrhythmic drug originated in China in 1970s. The effects of CRL on maximal upstroke velocity (Vmax) of action potentials were studied with standard microelectrode and computer in guinea pig papillary muscles. CRL depressed the Vmax. This effect was dependent on the rate of stimulations. The onset of use-dependent depression was monoexponential and dependent on drug concentration and rate of stimulations. The rate of recovery from use-dependent depression also followed a single exponential time course. CRL shifted the curve relating normalized Vmax to membrane potential in the hyperpolarizing direction. The onset rate was 0.156 +/- 0.025 AP-1 (RDB 50%), and offset rate (tau r) was 4.7 +/- 0.9 s. These suggest that CRL belongs to class Ia antiarrhythmic drugs.
常咯啉（CRL）是20世纪70年代起源于中国的一种新型抗心律失常药物。运用标准微电极和计算机研究了常咯啉对豚鼠乳头肌动作电位最大上升速度（Vmax）的影响。常咯啉使Vmax降低。这种作用取决于刺激频率。使用依赖性抑制的起始呈单指数形式，且取决于药物浓度和刺激频率。从使用依赖性抑制中恢复的速率也遵循单一指数时间进程。常咯啉使将归一化Vmax与膜电位相关的曲线向超极化方向移动。起始速率为0.156±0.025 AP-1（RDB 50%），抵消速率（τr）为4.7±0.9秒。这些表明常咯啉属于Ⅰa类抗心律失常药物。
