48h快速右房起搏致犬心房迷走神经重构的实验研究

Vagus nerve remodeling in a canine model of atrial fibrillation produced by 48 hours right atrium pacing

目的通过对快速心房起搏犬的神经相关因子的研究,观察右房快速起搏48h是否引起神经重构及其在房颤中的作用。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48h。通过GAP-43和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,均有有统计学意义(P<0.05)。此外,在房颤犬,右房GAP-43和CHAT的神经密度与左房有明显差别(P<0.05),镜下显示在每个样点心脏神经不均匀分布。结论 48h持续起搏犬右房形成阵发性房颤,可见明显的神经萌发和迷走神经重构且不均一分布。

ObjectivesTo evaluate nerve remodeling induced by 48 hours pacing of right atrium in a canine model.MethodsMongrel dogs of either sex were studied（n =12）.Rapid right atrial pacing was performed in 6 dogs for 48 hours to induce sustained AF.Tissues from 6 healthy dogs were used as controls.Immunocytochemical staining of cardiac nerves was performed using anti-growth-associated protein 43（GAP43） and anti-choline acetyltransferase（CHAT） antibodies.Nerve sprouting and vagus nerves remodeling were studied with these indexes.ResultsIn dogs with AF,the density of GAP-43 positive and CHAT positive nerves in the left and right atriums and the left and right auricular appendages was significantly（P〈0.05） higher than the nerve density in control tissues.Furthermore,in dogs with AF,the right atrium had significantly higher nerve density than the left atrium（P〈0.05）.Microscopic examinations revealed an inhomogeneous distribution of cardiac nerve.ConclusionSignificant nerve sprouting and vagus nerves remodeling are more obvious in the right atrium than in the left atrium in a canine model of sustained AF produced by 48 hours right atrial pacing.