E-4031对豚鼠心室肌细胞Na^+/Ca^(2+)交换电流的影响

Effects of E-4031 on Na^+/Ca^( 2+) exchange current in cardiac myocytes

采用全细胞电压钳技术的斜坡脉冲程序 ,观察E - 4 0 3 1对豚鼠心室肌细胞膜Na+/Ca2 +交换电流的影响。结果表明E - 4 0 3 10 0 1,0 1和 1 0 μmol/L分别使膜电位 +5 0mV时的Na+/Ca2 +交换电流相应增加 ( 11± 6) % ,( 5 9± 13 ) %和 ( 112± 2 5 ) % ,提示E - 4 0 3 1对Na+/Ca2

The effects of E-4031 on the Na +/Ca 2+ exchange current were studied in guinea pig ventricular myocytes using whole-cell voltage-clamp techniques with a ramp pulse protocol. The current increased (11±6)%,(59±13)% and (112±25)% in cells perfused with 0.01,0.1 and 1.0 μmol/L E-4031 respectively ( P <0.05). Results indicate that the concentration-dependent stimulating effects of E-4031 on Na +/Ca 2+ exchange current may be an important mechanism underling the positive intropic action of this new class Ⅲ antiarrhythmic drug.