| Description |
GS967 (GS-458967) is a potent, and selective inhibitor of cardiac late sodium current (late INa ) with IC50 values of 0.13 and 0.21 μM for ventricular myocytes and isolated hearts, respectively.
|
| Related Catalog |
|
| Target |
IC50: 0.13 μM (late INa , ventricular myocytes )and 0.21 μM (late INa , isolated hearts)[1]
|
| In Vitro |
GS967 (10, 100, 300 nM) completely attenuates the effect of ATX-II (10 nM) to increase action potential duration (APD) and APD variability in ventricular myocytes, with an apparent IC50 value of ∼10 nM and decreased the beat-to-beat variability of APD[1].
|
| In Vivo |
GS967 prevents and reverses proarrhythmic effects of the late INa enhancer ATX-II and the IKr inhibitor E-4031. GS967 significantly attenuates the proarrhythmic effects of methoxamine 1 clofilium and suppressed ischemia-induced arrhythmias[1]. GS967 causes a reduction of INaP in a frequency-dependent manner, consistent with use-dependent block (UDB). GS967 evokes more potent UDB of INaP (IC50=0.07 μM) than ranolazine (16 μM) and lidocaine (17 μM). GS967 is found to exert these same effects on a prototypical long QT syndromemutation (delKPQ)[2]. GS967 prevents ischemia-induced increases in alternans in the left atrium and left ventricle. GS967 reduces ischemia-induced increases in depolarization heterogeneity and repolarizationheterogeneity. GS967 does not alter heart rate, arterial blood pressure, PR and QT intervals, or QRS duration, but it mildly decreased contractility during ischemia, which was consistent with late INa inhibition[3].
|
| Animal Admin |
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]. Potet F, et al. Use-Dependent Block of Human Cardiac Sodium Channels by GS967. Mol Pharmacol. 2016 Jul;90(1):52-60. [3]. 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. [4]. 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.
|
