伊布利特对兔心房细胞快钠电流活性的影响

目的观察不同浓度伊布利特对心房细胞快钠通道的影响。方法新西兰纯种大耳白兔40只,随机分为正常对照组(Con),伊布利特10-7mol/L、10-6mol/L和10-5mol/L浓度组。利用胶原酶酶解法分离心房肌细胞,应用膜片钳全细胞记录方法,记录对照组及伊布利特3种浓度组心房细胞INa活性,并与正常对照组进行比较分析。结果INa峰值电流密度在对照组为-87.12±4.67pA/pF;伊布利特10-7mol/L、10-6mol/L和10-5mol/L组分别为-68.82±4.43,-45.26±3.46和-33.46±3.11pA/pF,伊布利特组较对照组有明显下降(P<0.05或0.01),伊布利特3组之间也有显著差异且呈浓度依赖性(P<0.05)。伊布利特组的INa稳态失活曲线浓度依赖性左移,INa再恢复明显减慢。结论伊布利特浓度依赖性的抑制心房细胞0相快钠电流,这可能是伊布利特治疗房性心律失常的部分离子通道机制。

Effects of Ibutilide on I_(Na) current in isolated atrial myocytes of rabbit

Objective To probe into the ion channel mechanism of Ibutilide antiarrythmic potential at celluar level,by studying the sodium current(I Na)of atrial cells of rabbit. Method New Zealand white rabbits were selected.Their hearts were cannulated via aorta and recorded on a Langendorff apparatus and perfused laterly.Single atrial cells were isolated enzymatically from rabbit left free wall,and I Na was recorded by using patch clamp technique in the whole cell configuration before and after perfusiong of 10-7,10...