室性心动过速时连接蛋白43含量与分布的变化

目的　探讨室性心动过速 (室速 )时心肌细胞连接蛋白 4 3(Cx 4 3)含量和分布的变化。方法　实验用日本大耳白兔 2 0只 ,随机分为对照组、30min室速组、6 0min室速组、12 0min室速组 4组。分别通过心室刺激复制室性心动过速动物模型 ,应用激光共聚焦显微镜技术和荧光免疫组织化学方法对其发生心律失常心肌连接蛋白 4 3的含量和分布进行定量分析。结果　 30min室速组连接蛋白 4 3像素密度较对照组减少 18.4 % (P <0 .0 5 ) ,6 0min室速组减少 38.0 % (P <0 .0 1) ,12 0min室速组减少 5 4 .8% (P <0 .0 1)。对照组各层间心肌细胞连接蛋白 4 3含量比较无显著差异 ,但心律失常后 ,中间层心肌细胞连接蛋白 4 3含量较其他层心肌细胞含量下降更明显 (P <0 .0 5或P <0 .0 1)。结论　室性心动过速时连接蛋白 4 3迅速降解 ,其分布也发生明显的改变 ,各层心肌细胞连接蛋白 4 3的降解程度也明显不均一。

Changes of connexin 43 content and distribution during ventricular tachycardia

Objective To investigate the changes of content and distribution of connexin 43(Cx 43) during ventricular tachycardia(VT).Methods 20 Japanese rabbits were randomly divided into control group(n=5),30 min VT group(n=5),60 min VT group(n=5) and 120 min VT group(n=5).The ventricular tachycardia was induced by right ventricular pacing.The content and distribution of Cx 43 of ventricular myocardium were studied by laser confocal microscopy and immunohistochemistry technique.Results There was a 18.4%,38.0% and 54.8% decrease of Cx 43 pixel density in 30,60 and 120 min VT groups seperately(P<0.05,0.01,0.01).There was not significant difference in the Cx 43 pixel density of each myocardial layer in control group,while the decrease of Cx 43 pixel density was more significant in the middle layer of myocardium after ventricular tachycardia(P<0.05 or P<0.01 ).Conclusion The Cx 43 degraded rapidly during rentricular pacing.Both content and distribution of Cx 43 change after ventricular tachycardia.The degradation of Cx 43 maybe different in different layers of myocardium.