快速右心房起搏致犬心房迷走神经重构的研究

目的 通过对快速心房起搏犬的神经相关因子的研究,观察右心房快速起搏48 h是否引起神经重构及其在心房颤动(房颤)中的作用.方法 健康杂种犬12只,随机分为房颤组(6只)和对照组(6只).右心房起搏600次/min、持续48 h.通过一种在发芽轴突生长丘中表达的蛋白质(GAP-43)和乙酰胆碱转移酶(CHAT)来了解心脏神经萌发和迷走神经的重构.结果 在房颤犬的左心房、左心耳、右心房和右心耳,GAP-43和CHAT的神经密度同对照组相比明显增高,差异均有统计学意义(P<0.05).此外,房颤犬的右心房GAP-43和CHAT的神经密度与左心房有明显差异(P<0.05),显微镜下显示每个样点心脏神经不均匀分布.结论 48 h持续起搏犬右心房形成阵发性房颤,可见明显的神经萌发和迷走神经重构且不均一分布.

Nerve remodeling in a canine model of atrial fibrillation induced by 48 hours right atrial pacing YU

Objective To evaluate the nerve remodeling induced by 48 hours right atrial pacing in a canine model. Methods Rapid right atrial pacing (600 beats/min) was performed in 6 mongrel dogs of either sex for 48 hours to induce sustained atrial fibrillation (AF). Six dogs without pacing served as controls. Cardiac nerves were immunocytochemically stained using anti-growth-associated protein 43 (GAP43) and anti-choline acetyltransferase (CHAT) antibodies to compare nerve sprouting and pneumogastric nerve remodeling between the 2 groups. Results In dogs with AF, the GAP43-positive and CHAT-positive nerve densities in the left atrium, left auricular appendage, right atrium and right auricular appendage were significantly higher than in control animals (all P <0.05). Moreover, nerve density was significantly higher in the right atrium than in the left atrium in dogs with AF. Microscopic examinations revealed an inhomogeneous distribution of cardiac nerves. Conclusion Significant nerve sprouting and pneumogastric nerve remodeling were evidenced in the right and left atrium in a canine model of sustained AF induced by 48 hours right atrial pacing.