GS967

Animal experiment:

Rats: Ventricular tachycardia or fibrillation are induced either by local aconitine injection (50 μg) in the left ventricular muscle of adult male rats or by arterial perfusion of 0.1 mM hydrogen peroxide in aged male rats. The left ventricular epicardial surface of the isolated-perfused hearts is optically mapped using fluorescent voltage-sensitive dye, and microelectrode recordings of action potentials are made adjacent to the aconitine injection site. The suppressive and preventive effects of GS967 (1 μM) against EAD/DAD-mediated ventricular tachycardia or fibrillation are then determined[2]. Rabbits: To determine the effect of GS967 on the inducibility of TdP by clofilium in the presence of methoxamine, rabbits are first treated with either vehicle or GS967 (in randomized manner) given as a 60 μg/kg bolus, followed by a 16 μg/kg/min infusion that is maintained for the duration of an experiment. After 10 minutes, methoxamine is infused intravenously at 15 μg/kg/min, followed 10 minutes later by clofilium at 100 nmol/kg/min. The incidences of premature ventricular contractions (PVCs), ventricular tachycardia (VT; defined as three or more consecutive abnormal beats), and TdP are determined from the ECG recordings[1].

References:

[1]. Belardinelli L, et al. A novel, potent, and selective inhibitor of cardiac late sodium current suppresses experimental arrhythmias. J Pharmacol Exp Ther. 2013 Jan;344(1):23-32.
[2]. Wei X, et al. Pre- and Delayed Treatments With Ranolazine Ameliorate Ventricular Arrhythmias and Nav1.5 Downregulation in Ischemic/Reperfused Rat Hearts. J Cardiovasc Pharmacol. 2016 Oct;68(4):269-279.
[3]. Potet F, et al. Use-Dependent Block of Human Cardiac Sodium Channels by GS967. Mol Pharmacol. 2016 Jul;90(1):52-60.
[4]. Bonatti R, et al. Selective late sodium current blockade with GS-458967 markedly reduces ischemia-induced atrial and ventricular repolarization alternans and ECG heterogeneity. Heart Rhythm. 2014 Oct;11(10):1827-35.