心房颤动致犬肺静脉肌袖缝隙连接蛋白40表达降低

目的探讨心房颤动时犬肺静脉肌袖缝隙连接蛋白40和43(Cx40,Cx43)基因及蛋白表达的变化及其意义。方法17只杂种犬随机分为心房颤动组(11只)和对照组(6只),房颤组经颈外静脉将电极置入右心耳快速起搏(400次/分)8周复制房颤模型,开胸取右上肺静脉近心房1cm内组织,用荧光实时定量PCR及Western blot技术检测缝隙连接蛋白40和43(Cx40,Cx43)mRNA及蛋白的表达量。结果房颤组和对照组犬肺静脉肌袖组织Cx40和Cx43的mRNA表达无显著性差异,房颤组Cx40蛋白表达明显低于对照组(P<0.05),Cx43蛋白表达无显著性差异。结论房颤可使肺静脉肌袖Cx40蛋白表达降低,缝隙连接发生重构,从而促进房颤的维持和稳定。

Expression reduction of gap-junctional protein connexin 40 in canine pulmonary vein with atrial fibrillation

objective To identify the changes of connexin 40 and connexin 43(Cx40,Cx43) mRNA and protein level in myocardial sleeves of canine pulmonary vein of atrial fibrillation.Methods Seventeen dogs were randomly divided into 2 groups: normal control group(SR,n=6) and atrial fibrillation(AF,n=11) group.The bipolar electrodes catheter was inserted through internal jugular to the upper right atrium in AF group,then atrial pacing was undergone at the frequency of 400 times per minute for 8 weeks.Samples were collected from right upper pulmonary veins.The mRNA and protein expression of Cx40 and Cx43 were assessed by real-time quantitative PCR and Western blot respectively.Results At the mRNA level,there was no significant difference in the expression of Cx40 and Cx43 between the two groups.Cx40 protein were significantly decreased in AF group as compared with SR group(P<0.05).The expression of Cx43 protein was not different in the two groups.Conclusion The Cx40 protein level is further reduced during atrial fibrillation.The gap-junctional remodeling is involved in the maintenance and stabilization of AF.