GS967

GS967, also known as GS-458967, is a highly selective late sodium channel current blocker. The selective inhibition of late INa with GS967 can exert antiarrhythmic effects by suppressing EAD- and DAD-mediated extrasystolic activity in PFs and PV and SVC sleeve preparations. Selective late INa inhibition with GS967 exerts potent protective effects against ischemia-induced depolarization and repolarization abnormalities in both atria and ventricles.

gs967 is a potent, selective and novel inhibitor of cardiac late sodium current (late ina) with ic50=0.13 μm in ventricular myocytes and ic50=0.21μm in isolated hearts. [1]when na+ channels in myocytes fail to inactivate after opening, na+ influx continues throughout the ap plateau. the resulting na+ current (ina) is referred to as late ina. its magnitude is increased in many pathologic conditions, such as in the failing and/or ischemic heart, in the heart exposed to oxidative stress, and in hearts of patients with congenital long qt3 syndromes. [1]in rabbit isolated ventricular myocytes, inhibition of peak ina by gs967 is in a concentration- and voltage-dependent manner with minimal use-dependent, it also decreases the na+ and ca2+ overload. in rabbit-isolated heart, gs967 abolishes tdp induced by atx-ii or e-4031. [1]in anesthetized rabbit, gs967 reduces mapd90 but did not alter cardiac conduction time; it also prevents the induction of arrhythmic activity and tdp by clofilium and decreases the incidence of ischemia-induced arrhythmias. [1]

1. belardinelli l, liu g, smith-maxwell c et al. a novel, potent, and selective inhibitor ofcardiac late sodium current suppresses experimental arrhythmias. j pharmacol exp ther. 2013 jan;344(1):23-32.