Antiarrhythmic efficacy of CPUY102122, a multiple ion channel blocker, on rabbits with ischemia/reperfusion injury.

BACKGROUND: The antiarrhythmic potential of a novel multichannel blocker CPUY102122 (CY22) was investigated in the present study. METHODS: The effect of CY22 on rapid delayed rectifier potassium channel current (IKr) was studied using whole-cell patch clamp techniques in Chinese Hamster Ovary cells stably expressing human Ether-à-go-go-Related Gene. We further evaluated the antioxidant effects of CY22 and demonstrated the reversal of connexin down-regulation in the development of cardiac ventricular arrhythmias, which was produced using coronary ligation/reperfusion in rabbits. CY22 and Amiodarone were administered 30min prior to the procedure. Next, electrocardiograms were recorded, protein expression of left ventricular Connexin43 (Cx43), non-phosphorylation-Cx43 (np-Cx43), Rac-1 and gp-91[phox] were assayed using Western blot analysis, microstructural changes in the myocardium were observed and redox system activity was assayed. RESULTS: CY22 inhibited IKr in a concentration-dependent manner with IC50 value of 2.8±0.8µmol/L. CY22 treatment significantly decreased T-wave amplitude and QTc arrhythmic scores and ameliorated the shape of the infarcted myocardium compared to the model group. CY22 decreased the serum levels of creatine kinase, lactate dehydrogenase, and myocardial levels of malondialdehyde, as well as increased superoxide dismutase activity. Cx43 expression in the left ventricle was significantly increased by CY22 treatment, which significantly decreased np-43 expression, Rac-1 activity and gp-91[phox] protein expression. CONCLUSIONS: These results indicated that CY22 has both antiarrhythmic and cardiovascular protective effects partly by blocking IKr, the production of antioxidants and protection of Cx43.

Discovery of 1-aryloxyethyl piperazine derivatives as Kv1.5 potassium channel inhibitors (part I).

Kv1.5 potassium channel is an efficacious and safe therapeutic target for the treatment of atrial fibrillation (AF), the most common arrhythmia that threatens human. Herein, by modifying the hit compound 7k from an in-house database, 48 derivatives were synthesized for the assay of their Kv1.5 inhibitory effects by whole cell patch clamp technique. Six compounds which showed better potency than the positive compound dronedarone were selected for the next evaluation of their drug-like properties. Compound 8 exhibited balanced solubility and permeability. It also showed acceptable pharmacodynamics profile with very low acute toxicity. Taking all these data into account, compound 8 can serve as a promising lead for the development of novel therapeutic agent for the treatment of AF.