Wang Q S, Sun W, Jia C Q, Liu T F
Department of Physiology, Zhangjiakou Medical College, China.
Zhongguo Yao Li Xue Bao. 1991 Sep;12(5):449-52.
The dual effects of nicardipine (Nic) on the automatic activity of sinoatrial (SA) node cell in rabbit heart had been observed using intracellular microelectrodes. Superfused with Nic 0.1, 0.5, 1.0, and 5.0 mumol.L-1 for 10 min, the spontaneous rate was decreased by 32%, 42%, 47%, and 69%, respectively. However, by superfusing with Nic 0.05 mumol.L-1, the spontaneous rate and the amplitude of action potentials were increased by 12% and 13% respectively. Nic 5.0 mumol.L-1 inhibited the positive chronotropic effects of isoproterenol and nicotine. The results suggest that Nic may block the calcium influx in SA node cells.
采用细胞内微电极观察了尼卡地平（Nic）对兔心脏窦房结细胞自律性的双重作用。用0.1、0.5、1.0和5.0μmol·L-1的尼卡地平灌流10分钟后，自发频率分别降低了32%、42%、47%和69%。然而，用0.05μmol·L-1的尼卡地平灌流时，自发频率和动作电位幅度分别增加了12%和13%。5.0μmol·L-1的尼卡地平抑制了异丙肾上腺素和尼古丁的正性变时作用。结果表明，尼卡地平可能阻断窦房结细胞的钙内流。
