对－呋喃硝苯啶对豚鼠心脏乳头状肌动作电位参数的影响

Effects of para-fural nifidipine on action potential of isolated papillary muscles in guinea pigs

对－呋喃硝苯啶（Ｐ－Ｎｉｆ）是新近合成的一种药物，为钙拮抗剂硝苯啶的呋喃衍生物。本文采用微电极技术，在离体豚鼠乳头肌上，就Ｐ－Ｎｉｆ对乳头肌细胞跨膜动作电位离子流的影响进行了观察。发现３０μｍｏｌ／Ｌ的Ｐ－Ｎｉｆ可缩短快反应细胞的ＡＰＤ５０、ＡＰＤ９０及ＡＰＤ，缩短ＥＲＰ，同时明显降低慢反应动作电位的幅度和ＡＰＤ５０、ＡＰＤ９０及Ｖｍａｘ，提示Ｐ－Ｎｉｆ的作用和Ｎｉｆ相似，主要是阻断钙通道。

The recently synthesized para fural nifidipine(P-Nif) is afural derivant of nifidipine. In this experiment we observed the effects of P-Nif on action potential of isolated papillary muscles in guinea pigs by microelectrode technique. It was shown that p-Nif 30 μmol/L reduced action potential duration at 50%, 90% and 100% repolarization (APD50,APD90,APD) and prolonged the effective refractory period(ERP).In slown response action potentials P-Nif(30 μmol/7) also reduced APD50,APD 90,APD,and,in the meantime, decreased APA and Vmax. These findings suggest that P-Nif exerts effects analogous to Nif by blocking the calcium channels.