【摘要】 目的研究心房颤动(房颤)心房交感神经过度支配的机制。方法14只犬被随机分为假手术组和起搏组,起搏组犬右心房400次/分起搏6周建立房颤犬模型。起搏6周后,免疫组织化学法检测两组犬左右心房前壁神经萌出和交感神经分布;分别应用实时定量RT-PCR法和蛋白印迹法检测左右心房前壁β-神经生长因子(β-NGF)基因和蛋白表达。结果心房快速起搏引起心房显著神经萌出和交感神经不均一性过度支配,右心房前壁神经萌出和交感神经密度大于左心房前壁。起搏组犬左右心房前壁心房肌β-NGF基因和蛋白表达显著增加,且右心房前壁心房肌β-NGF含量高于左心房前壁。两组犬心房肌β-NGF蛋白含量与局部交感神经密度显著正相关。结论心房肌β-NGF过度表达可能是房颤心房不均一性交感神经过度支配的主要机制。更多还原

【Abstract】 Objective To study the mechanisms of atrial sympathetic hyperinnervation during experimental atrial fibrillation(AF).Methods Fourteen dogs were divided into sham-operated group and pacing group.Canine models of AF produced by right atrial pacing at 400 beats per minute for 6 weeks in pacing group.After 6-week tachypacing,the degree of nerve sprouting and sympathetic innervation at right atrial anterior wall(RAAW) and left atrial anterior wall(LAAW) were quantified by immunohistochemis try.Atrial β-nerve growth factor(β-NGF) mRNA and protein expression at RAAW and LAAW were assessed by real-time quantitative RT-PCR and Western-blot respectively.Results Atrial tachypacing induced significant nerve sprouting and sympathetic hyperinnervation at RAAW and LAAW.The magnitude of nerve sprouting and sympathetic hyperinnervation was higher in the RAAW than in the LAAW.Furthermore,atrial pacing also resulted in upregulation of atrial β-NGF mRNA and protein expression,which were more pronounced in RAAW compared with LAAW,and atrial β-NGF protein levels correlated positively with the density of local sympathetic nerves.Conclusion Atrial inhomogeneous upregulation of atrial β-NGF expression underlies the mechanism of heterogeneous sympathetic hyperinnervation during AF.更多还原