On the Mechanism of Antifibrillatory Effect of Afobazole

Effect of afobazole on the threshold of electrical fibrillation of the heart was studied on anesthetized rats with intact myocardium. It was shown that the drug considerably increased the threshold of electrical fi brillation of the heart, being not inferior to reference class I antiarrhythmic drugs (lidocaine and procainamide) according to V. Williamse classification. Against the background of preliminary injection of σ-receptor antagonist haloperidol, afobazole exhibited no antifibrillatory activity. These findings and analysis of published reports suggest that antifibrillatory activity of afobazole is determined by its antagonistic influence on σ₁-receptors localized in cardiomyocyte cytosol.