奎尼丁与二氢奎尼丁对豚鼠乳头肌动作电位影响的对比研究

Comparison on Action Potential of Guinea-Pig Papillary Muscles of Quinidine and Dihydroquinidine

应用经典玻璃微电极方法对比研究不同浓度奎尼丁(Q)与二氢奎尼丁(DHQ)对豚鼠乳头肌动作电位的影响。随药物浓度递增,两药均使动作电位时程(APD_(30))逐渐延长,O 相最大除极速度(Vmax)还渐降低,但 Q 作用的高峰浓度在20μmol/L,而 DHQ 在10μmol/L,DHQ≤10μmol/L 时对V_(max)的作用大于 Q。提示,DHQ 对心肌细胞动作电位的影响大于 Q。

The effects of quinidine(Q)and dihydroquinidine(DHQ)on the action potential of guinea pig papillary muscles were studied by using classic microelectrode technique.APD_(90)was prolonged and V__(max)was decreased as a function of concentration,but the effects of Q peaked at 20μmol/L,while those of DHQ at 10μmol/L.The effects of DHQ on V_(max)are stronger than those of Q when the concentration of drugs≤10μmol/L.It suggests that the effects of DHQ on the action potential of the myocardium are stronger than those of Q.