Inhibition of late sodium current suppresses calcium-related ventricular arrhythmias by reducing the phosphorylation of CaMK-II and sodium channel expressions.

ABSTRACT: Cardiac arrhythmias associated with intracellular calcium inhomeostasis are refractory to antiarrhythmic therapy. We hypothesized that late sodium current (I _Na) contributed to the calcium-related arrhythmias. Monophasic action potential duration at 90% completion of repolarization (MAPD₉₀) was significantly increased and ventricular arrhythmias were observed in hearts with increased intracellular calcium concentration ([Ca²⁺]_i) by using Bay K 8644, and the increase became greater in hearts treated with a combination of ATX-II and Bay K 8644 compared to Bay K 8644 alone. The prolongations caused by Bay K 8644 and frequent episodes of ventricular tachycardias, both in absence and presence of ATX-II, were significantly attenuated or abolished by la

SUBMITTER: Wei XH 

PROVIDER: S-EPMC5430524 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature