Liu D Q, Zhou S S, Zhao D H, Sheng B H
Department of Pharmacology, Fourth Military Medical Univesity, Xi-an, China.
Zhongguo Yao Li Xue Bao. 1993 Mar;14(2):164-7.
Effects of furyl-dihydropyridine (FDP) on action potential of rabbit ventricular myocardium in vivo were observed with floating microelectrode technique. FDP 0.5 mg.kg-1 i.v. increased APD30 from 104 +/- 7 to 127 +/- 7 ms, APD90 from 146 +/- 10 to 177 +/- 9 ms (P < 0.01, n = 7), decreased the heart rate from 230 +/- 18 to 203 +/- 20 bpm (P < 0.05). Nifedipine (Nif) 0.5 mg.kg-1 i.v. reduced APD and increased the HR in rabbit. In guinea pig left atrium, FDP and Nif decreased the APD, the effects of acetylcholine to shorten the APD was antagonized by FDP 1 mumol.L-1. In rabbit's sinoatrial nodes, FDP 0.5, 1 mumol.L-1 also suppressed the APA and increased the spontaneous sinus cycle length (SCL) and APD50. These results indicate that FDP may inhibit the Ca2+ and K+ currents of myocardium.
采用浮置微电极技术观察了呋喃二氢吡啶（FDP）对家兔在体心室肌动作电位的影响。静脉注射FDP 0.5mg·kg-1可使动作电位30%复极期（APD30）从104±7ms增至127±7ms，动作电位90%复极期（APD90）从146±10ms增至177±9ms（P<0.01，n=7），心率从230±18次/分钟降至203±20次/分钟（P<0.05）。静脉注射硝苯地平（Nif）0.5mg·kg-1可使家兔的动作电位时程缩短，心率加快。在豚鼠左心房，FDP和Nif均可使动作电位时程缩短，1μmol·L-1的FDP可拮抗乙酰胆碱缩短动作电位时程的作用。在兔窦房结，0.5、1μmol·L-1的FDP也可抑制动作电位幅度（APA），延长窦性周期长度（SCL）和动作电位50%复极期（APD50）。这些结果表明，FDP可能抑制心肌的钙电流和钾电流。
