Effects Of Ibutilide On The Sodium Ionic Channel Currents In Rabbit Ventricular Myocytes

Objective: Arrhythmias is very common in clinical practice, especially ventricular arrhythmias which is the most important reason of sudden cardiac death. It is one of the most important task to seek new drugs to inhibit the ventricular arrhythmias. A new antiarrhythmic drug of class III-Ibutilide is effective and safe in patients with atrial flutter and atrial fibrillation. It is discovered that Ibutilide is also useful to inhibit ventricular arrhythmias in some animal experiments and clinical studies. Sodium channel current(INa) is one of important ion channels which lead to ventricular arrhythmias. To explore the cellular basis of the Ibutilide's effect on ventricular arrhythmias, the current and kinetics of INa from rabbit mid-myocardial cells(M cells) of left ventricular was recorded by using patch clamp techniques in the whole-cell configuration with or without Ibutilide.Material and methods:1 Experimental animals: Sixty healthy rabbits (Newsland pure white, Come from Hebei medical university) of either sex weighing 1.5 to 2 kg were used in the study. The rabbits were divided into three groups: (1) Twenty-five rabbits was used in high-concentration of Ibutilide (10-5mol/L). (2) As well as the...