Effects of a novel class III antiarrhythmic agent, CPUY11018, on rat atrial fibrillation

CPUY11018 has anti‐atrial fibrillation (AF) effects in rats. The effects of CPUY11018 on the transient outward K + current ( I to ) and ultra‐rapid delayed rectifier K + current ( I Kur ) were studied using whole‐cell patch clamp techniques and an acetylcholine (ACh)‐CaCl 2 induced AF model. CPUY11018 inhibited I to and I Kur in a concentration‐dependent manner with IC 50 values of 18.5 and 1.7 µM, respectively. Inhibition was independent of the depolarizing voltage. In the AF ACh‐CaCl 2 model, AF duration was effectively shortened after treatment with 5 mg/kg CPUY11018 for 4 days. These results indicate that CPUY11018 is effective in treating AF partly by blocking I to and I Kur . Drug Dev Res 71, 2010. © 2010 Wiley‐Liss, Inc.