二乙酰基莲心碱对心室肌细胞膜钠、钙通道的影响

目的 :探讨二乙酰基莲心碱 (Diacetyl linesinine)对家兔心室肌细胞膜钠、钙离子通道的影响。方法 :选取10只体重 1.5～ 2 .0kg的健康新西兰大耳白兔 ,酶解法分离单个心室肌细胞 ,应用全细胞膜片钳技术观察 10 ,30 ,10 0 μmol·L-1的二乙酰基莲心碱对心室肌细胞膜钠通道和钙通道的作用。结果 :二乙酰基莲心碱浓度依赖性减少钠电流和L 型钙电流 ,10 ,30 ,10 0 μmol·L-1的二乙酰基莲心碱可分别使峰值钠电流降低 4 0 .7% ,78.4 %和 89.4 % ;使峰值L 型钙电流降低 5 6 .6 % ,6 5 .7%和 73.6 %。另外 ,二乙酰基莲心碱可使钠通道灭活曲线左移 ,并可减慢钠通道灭活后的恢复过程。结论 :二乙酰基莲心碱对钠电流及L 型钙电流具有浓度依赖性阻滞作用 ,并可作用于钠通道的失活态 ,这些可以部分解释其抗心律失常作用机制。

Effects of Diacetyl-linesinine on Sodium Ion Channel and L-type Calcium Ion Channel in Isolated Ventricular Myocytes

Objective: To study the effects of diacetyl-linesinine on sodium and calcium ion channels in isolated ventricular myocytes by using whole-cell patch clamp technique.Methods: Ten rabbits which weight from 1.5～2.0 kg were involved. Single ventricular cell of rabbit was obtained by an enzymatic dissociation method. The whole-cell patch clamp recording technique was used to record the changes of sodium current (I_ Na ),L-type calcium current (I_ Ca,L ) following the administration of diacetyl-linesinine at 10,30 and 100 μmol·L -1 . Results: Diacetyl-linesinine 10,30 and 100μmol·L -1 decreased I_ Na and I_ Ca,L significantly in a concentration-dependent manner. Peak I_ Na was reduced 40.7%,78.4%,and 89.4%,respectively at diacetyl-linenine 10,30 and 100 μmol·L -1 . Peak I_ Ca,L was reduced 56.6%,65.7% and 73.6% respectively at diacetyl-linenine 10, 30 and 100 μmol·L -1 . In addition,diacetyl-linesinine delayed the recovery time course of I_ Na from inactive state. Conclusion: Diacetyl-linesinine blocked I_ Na and I_ Ca,L in a concentration-dependent manner. In addition,diacetyl-linesinine affected the channel kinetics of I_ Na and delayed the recovery time course of I_ Na from inactive state.