Minhui Wang1, Jiaojiao Shan2, Qian Yang3, Xianglei Ma4, Sisi Jin5, Xiaoke Guo6, Qidong You7, Yiqun Tang8. 1. Department of Clinical Pharmacy, China Pharmaceutical University, Nanjing, China; Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, China. Electronic address: wmh_yjs@163.com. 2. Department of Clinical Pharmacy, China Pharmaceutical University, Nanjing, China. Electronic address: zixinzizu@126.com. 3. Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing, China. Electronic address: cpuyangqian816@163.com. 4. Department of Clinical Pharmacy, China Pharmaceutical University, Nanjing, China. Electronic address: myword3477@163.com. 5. Department of Clinical Pharmacy, China Pharmaceutical University, Nanjing, China. Electronic address: jss393900019@163.com. 6. Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing, China. Electronic address: kexin95@126.com. 7. Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing, China. Electronic address: youqidong@gmail.com. 8. Department of Clinical Pharmacy, China Pharmaceutical University, Nanjing, China. Electronic address: tyq@cpu.edu.cn.
Abstract
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.
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.