Effects of combined amiodarone and antiarrhythmic peptide use on the cardiac gap junctions and incidence of induced ventricular arrhythmias in healed myocardial infarction rabbit models
10.3760/cma.j.issn.0253-3758.2010.12.012
- VernacularTitle:胺碘酮与抗心律失常肽合用对陈旧性心肌梗死兔心缝隙连接蛋白43和室性心律失常诱发率的影响
- Author:
Lian-Dong LI
1
;
Cun-Tai ZHANG
;
Lei RUAN
;
Ming-Ke NI
;
Yan FANG
;
Guo-Qiang WANG
;
Xing-Fen WANG
Author Information
1. 郑州人民医院
- Keywords:
Myocardial infarction;
Tachycardia,ventricular;
Amiodarone;
Anti-arrhythmia agents;
Connexin 43
- From:
Chinese Journal of Cardiology
2010;38(12):1102-1107
- CountryChina
- Language:Chinese
-
Abstract:
Objective The aim of this study is to observe the effect of combined amiodarone and antiarrhythmic peptide (AAP10) use on the incidence of induced ventricular arrhythmias in healed myocardial infarction (MI) rabbits. Methods Twenty Japanese rabbits underwent thoracotomy without coronary artery ligation( Sham, group A) ,the middle left circumflex branch were ligated to induce MI in 180 Japanese rabbits. Eight weeks after operation, 124 rabbits survived MI operation and were divided into four groups: control group (group B, n =31 ), amiodarone group (group C, n =31 ), AAP10 group (group D,n =31 ) and amiodarone plus AAP10 group ( group E, n =31 ). The A and B and D groups were treated with saline 2 ml/d, the C and E groups were treated with 2 ml saline containing amiodarone 100 mg· kg-1·d-1. All rabbits were examined by echocardiogram at 12 weeks after operation, then anesthetized by sodium barbital, the left wedge ventricular preparations were cannulated and artery perfused by Tyrode's solution in vitro in the absence (Group A, B and C) and presence of AAP10 (500 nmol/L, Group D and E). The volume electrocardiogram, QT Interval, QRS interval, effective refractory period (ERP), the T-peak to Tend interval ( Tp-e ), and ventricular tachycardia episodes induced by programmed stimulation were recorded.The Tp-e/QT ratio was calculated. After perfusion, gap junctions protein connexin 43 (Cx43) expression was detected by Western blot and immunofluorescence. Results The incidence of induced ventricular tachycardia episodes of group A, B, C, D, E was 0, 62. 5%, 26. 9%, 40.0%, 22. 2% respectively. The incidence of induced ventricular tachycardia episodes of group E was less than group B. The Tp-e/QT ratio in group B, C, D were greater than in group A. The Tp-e/QT ratio of group E was less than group B. The myocardial Cx43 in the group B was down-regulated and disorganized compared to group A, up-regulated in group C and E compared to group B, up-regulated in group E compared to group D. The Cx43 in the heart of group D and E were well organized than in group B and C. Conclusions The artery perfused rabbits wedge preparations with healed myocardial infarction with high incidence of induced ventricular tachycardia episodes are good platform for ventricular arrhythmias research. Combined amiodarone and AAP10 use could decrease the Tp-e/QT ratio and the incidence of induced ventricular tachycardia episodes. Amiodarone and AAP10have synergistic effects on upregulating Cx43 and preventing ventricular arrhythmias in this rabbit model of healed myocardial infarction.
