环维黄杨星D返针晶结晶体对豚鼠心室肌细胞动作电位的影响

目的:观察环维黄杨星D(Cyclovirobuxine D,CVB-D)返针晶结晶体对豚鼠单个心室肌细胞动作电位的影响。方法:使用Langendorff灌流系统离体灌流心脏,急性酶解法分离获得心肌细胞。全细胞膜片钳技术电流钳模式记录动作电位。Tyrode氏液和药物溶液交替反复灌流单个心室肌细胞。结果:CVB-D中浓度组用药后动作电位0相除极幅度(APA)从(113.3±6.3)mV下降至(110.2±6.4)mV(n=6,P0.01),复极至50%时动作电位时程(APD50)从(616.3±68.0)ms延长至(657.4±79.5)ms(n=6,P0.01),复极至90%时动作电位时程(APD90)从(633.5±71.2)ms延长至(669.2±74.4)ms(n=6,P0.01),复极50%至90%动作电位时程(APD50-90)从(15.9±6.0)ms延长至(20.1±5.2)ms(n=6,P0.01),动作电位3相复极速率(V3)从(-2.6±0.8)V/s减慢至(-2.4±0.7)V/s(n=6,P0.01)。Tyrode氏液和高浓度药物溶液交替反复灌流后APD50-90呈递增趋势而V3呈递减趋势,其他指标的变化趋势与中浓度组一致。CVB-D低浓度组各项指标的变化趋势缺乏统计学意义。结论:体外应用CVB-D返针晶结晶体引起心室肌细胞APA减小,APD50,APD90,APD50-90延长,V3减慢。以上影响可能是其在临床上具有增强心肌收缩力和抗心律失常作用的药理机制。

Effect of Cyclovirobuxine D on the Action Potentials ofVentricular Myocytes in Guinea Pig

Objective: To investigate the effect of Cyclovirobuxine D(CVB-D) on action potentials in isolated guinea pig ventricular myocytes. Methods: The single myocytes were enzymatically obtained from the guinea pig hearts and the action potentials were examined by whole-cell patchclamp technique. Results: 4×10^-4 g/L CVB-D decreased action potential amptitude(APA)from 113.3±6.3 mV to 110.2±6.4 mV(n=6, P<0.01), prolonged action potential duration of repolarization 50%(APD₅₀)from 616.3±68.0 ms to 657.4±79.5 ms(n=6, P<0.01),prolonged action potential duration of repolarization 90%(APD₉₀)from 633.5±71.2 ms to 669.2±74.4 ms(n=6, P<0.01), Prolonged action potential duration of repolarization 50% to repolarization 90%(APD_50-90)from 15.9±6.0 ms to 20.1±5.2 ms(n=6, P<0.01),and decreased decay slope of phase 3 (V₃) from -2.6±0.8 V/s to -2.4±0.7 V/s(n=6, P<0.01).Compared with the baseline,4×10^-3 g/L CVB-D makes the APD_50-90 pass to increase trend gradually,but the variety trend of the V₃ decrease gradually, other index sign varieties are consistent. Conclusion: CVB-D decreased APA and V₃, and prolonged APD₅₀,APD₉₀,APD_50-90,which may be its mechanism of positive inotropic effect and antiarrhythmic effect.