Zha Z, Lan T, Zhou Z, Yang Z
Hua Xi Yi Ke Da Xue Xue Bao. 1990 Jun;21(2):159-62.
This study adopted intracellular microelectrode technic to observe the effect of OPC-8212 (Vesnarinone) on intracellular potential of isolated canine ventricular papillary muscle. The record and data processing were completed by computerized intellective instrument designed by ourselves. The results of intracellular record in 14 canine ventricular papillary muscle showed no significant change in the resting potential (RP), amplitude of action potential (APA) and maximum depolarize velocity of 0 phase (Vmax). But significantly increased whole duration of action potential (APT). The duration of repolarization to 1/3 (APD 1/3) and to 2/3 (APD 2/3) significantly increased too. The plateau phase raised. These results suggest that K+ permeability at resting myocardiac cell membrane may have not been effected by OPC-8212. Activation of the fast sodium channel may have not been effected too. The results of our studies also suggest that inward flow of Ca2+ increased. The delayed outward K+ (Ik) and the inward, rectifying K+ current (Ik1) possible decreased. Thus, the OPC-8212 might become a nonglucoside and noncatecholamine new positive inotropic drug.
本研究采用细胞内微电极技术观察OPC - 8212（维司力农）对离体犬心室乳头肌细胞内电位的影响。记录和数据处理由我们自行设计的计算机智能仪器完成。对14条犬心室乳头肌细胞内记录的结果显示，静息电位（RP）、动作电位幅度（APA）和0期最大去极化速度（Vmax）无明显变化。但动作电位全程时间（APT）显著增加。复极化至1/3（APD 1/3）和2/3（APD 2/3）的时间也显著增加。平台期升高。这些结果提示，静息心肌细胞膜上的K⁺通透性可能未受OPC - 8212影响。快钠通道的激活可能也未受影响。我们的研究结果还提示，Ca²⁺内流增加。延迟外向K⁺电流（Ik）和内向整流K⁺电流（Ik1）可能减小。因此，OPC - 8212可能成为一种非糖苷、非儿茶酚胺类新型正性肌力药物。
