CAJ | 학술논문

目的探讨心房颤动(AF)犬上腔静脉(SVC)肌袖缝隙连接蛋白(Cx)含量和分布改变与迷走神经的关系.方法 24只杂种犬,分为3组:假手术组(Sham组)、切除上腔静脉-主动脉根部(SVC-AO)脂肪垫组(RM组)和保留SVC-AO脂肪垫组(RS组).RM组和RS组植入起搏器起搏6周,以程序刺激或猝发刺激诱发建立AF犬模型;Sham组植入起搏器但不起搏.取SVC肌袖组织行Cx40、Cx43免疫荧光染色并定量分析,透射电镜观察缝隙连接(GJ)超微结构.结果 RS组持续性AF诱发率为71.4%,高于RM组(P＜0.01).Sham组和Rs组Cx40、Cx43表达高于RM组(P＜0.05);RS组Cx40、Cx43表达高于Sham组(P＜0.05).Sham组和RM组Cx40、Cx43端/侧比值高于RS组(P＜0.05).RS组GJ通道变宽,出现肌溶解和线粒体空泡状改变.结论迷走神经可能通过介导SVC肌袖Cx重构而使AF易于发生和维持;切除SVC-AO脂肪垫可减弱此效应.
목적 탐토심방전동(AF)견상강정맥(SVC)기수봉극련접단백(Cx)함량화분포개변여미주신경적관계.방법 24지잡충견,분위3조:가수술조(Sham조)、절제상강정맥-주동맥근부(SVC-AO)지방점조(RM조)화보류SVC-AO지방점조(RS조).RM조화RS조식입기박기기박6주,이정서자격혹졸발자격유발건립AF견모형;Sham조식입기박기단불기박.취SVC기수조직행Cx40、Cx43면역형광염색병정량분석,투사전경관찰봉극련접(GJ)초미결구.결과 RS조지속성AF유발솔위71.4%,고우RM조(P＜0.01).Sham조화Rs조Cx40、Cx43표체고우RM조(P＜0.05);RS조Cx40、Cx43표체고우Sham조(P＜0.05).Sham조화RM조Cx40、Cx43단/측비치고우RS조(P＜0.05).RS조GJ통도변관,출현기용해화선립체공포상개변.결론 미주신경가능통과개도SVC기수Cx중구이사AF역우발생화유지;절제SVC-AO지방점가감약차효응.
Objective To investigate the relationship between cardiac vagus nerves and changes of connexins(Cx)and intracellular gap junction(GJ)distribution pattern in superior vena cava(SVC)myosleeve in dog with atrial fibrillation(AF).Methods Twenty four hybrid dogs were divided into sham operation group(Sham group,n=8),SVC-AO fat pad removed group(RM group,n=8)and SVC-AO fat pad reserved group(RS group,n=8).In RM group and RS group,right atrial pacing was performed at a frequency of 500～650/min for 6 weeks to establish AF model.AF was induced by programmed stimulation or burst stimulation of atrial pacing.The expression and distribution of Cx40 and Cx43 in the SVC myosleeve tissue in three groups were analyzed by immunofluorescence staining.Transmission electron microscopy was used to observe the uhrastructural organization of gap junction(GJ).Results The rate of inducing sustained AF(＞ 15 min)in RS group was significantly higher than that in RM group (P ＜ 0.01).The expression of Cx40 and Cx43 in the SVC myosleeve in sham group and RS group were significantly higher than that in RM group(P ＜ 0.05).Furthermore,the expression of Cx40 and Cx43 in RS group were obviously higher than that in sham group(P ＜0.05).The ratio of end-to-end to side-to-side in RS group was lower than that in Sham group and RM group.Comparing with RM group,the channel of GJ became shorter and wider in RS group(P ＜0.05).Sarcomere was dissolved and mitochondrion showed vacuole degeneration in RS group.Conclusion The remodeling of Cx40 and Gx43 in SVC myosleeve tissue may be mediated by vagus nerves.It is conducive to the maintenance and stability of AF.However,this effect can be weakened by removing SVC-AO fat pad of canine.