Dofetilide对成年豚鼠心室肌细胞钠钙交换的影响  

Effect of dofetilide on Na^+/Ca^(2+) exchange in ventricular myocytes of adult guinea pigs

作　　者：张轩萍[1] 牛拴成[1] 张明升[1] 武冬梅[1] 吴博威[2] 

机构地区：[1]山西医科大学药理学教研室,山西太原030001 [2]山西医科大学生理学教研室,山西太原030001

出　　处：《中国药理学通报》2004年第12期1366-1369,共4页Chinese Pharmacological Bulletin

基　　金：国家自然科学基金资助项目 ;No 3 0 170 3 46

摘　　要：目的　研究dofetilide对豚鼠心室肌细胞Na+ /Ca2 + 交换电流的影响。方法　酶法分离成年豚鼠心室肌细胞 ,全细胞膜片钳方式、斜坡电压刺激程序 (从钳制电位 - 4 0mV去极化至 +6 0mV ,然后以 90mV/s的速率超极化至 - 12 0mV)记录Na+ /Ca2 + 交换电流 (INa/Ca)及dofetilide 0 0 3～ 1 0μmol·L-1对该电流的影响。结果　dofetilide 0 0 3～ 1 0μmol·L-1浓度依赖性地增强Na+ /Ca2 + 交换外向及内向电流 ,对外向电流的EC50 (5 0 %最大效应浓度 )为 0 178μmol·L-1(95 %可信限为 0 0 4 0～ 0 787μmol·L-1) ,对内向电流的EC50 为 0 178μmol·L-1(95 %可信限为 0 0 38～ 0 84 2μmol·L-1)。结论　dofetilide对豚鼠心室肌细胞Na+ /Ca2 +交换外向及内向电流均有浓度依赖性的明显增强作用。Aim This paper aims at investigating the effect of dofetilide on Na+/Ca 2+exchange in ventricular myocytes of adult guinea pigs. Methods Rapid enzymatic isolation procedure was performed to get single ventricular myocytes from adult guinea pigs. After the whole cell configuration was formed, a ramp voltage-clamp pulse depolarized from a holding potential of -40 mV to +60 mV, then hyperpolarized to -120 mV at a rate of 90 mV/s to record the Na+/Ca 2+ exchange current (I Na/Ca) and the influence of dofetilide from 0.03～1.0 μmol·L -1. Result Dofetilide from 0.03～1.0 μmol·L -1 concentration-dependently increased the I Na/Ca in both outward and inward mode. The EC 50 of dofetilide on I Na/Ca in outward and inward mode of NCE was 0.178 μmol·L -1 (95% confidence interval was 0.040～0.787 μmol·L -1) and 0.178 μmol·L -1 (95% confidence interval was 0.038～0.842 μmol·L -1), respectively. Conclusion Dofetilide concentration-dependently increased the outward and inward Na+/Ca 2+ exchange current in ventricular myocytes of adult guinea pigs.

关 键 词：DOFETILIDE 钠钙交换 心室肌细胞 膜片钳 

分 类 号：R-332[医药卫生] R322.11