快速起搏兔右房致自主神经电活动改变和重构的研究

目的研究自主神经系统(ANS)在心房颤动(AF)发生和维持中的作用。方法成年新西兰大白兔20只,随机分为假手术组(n=10)和模型组(n=10)。模型组给予24h快速心房起搏。以自主神经放电活动变化作为快速起搏后神经重构的参考指标,统计指标是放电积分幅度(AID),放电时程(TCD),放电间隔时程(TCDI)。并应用荧光免疫技术研究自主神经生长相关蛋白(GAP43),乙酰胆碱转移酶(ChAT),酪氨酸羟化酶(TH)的分布密度和再生。结果与假手术组比较,模型组迷走神经AID增加(P<0.001);而TCD和TCDI无延长(P均>0.05);模型组交感神经AID降低(P=0.002);而TCD延长,TCDI缩短(P=0.000)。GAP43、ChAT和TH假手术组依次呈阳性、弱阳性、弱阳性。而模型组依次呈强阳性、阳性、阳性。结论24h快速心房起搏后,心脏神经纤维存在形态、分布及密度的改变,即神经重构。

The changes of discharge activity and remoding of autonomic nerves in rapid atrial pacing rabbits

Objective To investigate changes of discharge activity and remoding of autonomic nervous in rapid atrial pacing （RAP） right atrium of rabbits. Methods Twenty New Zealand white rabbits were randomly divided into 2 groups ： sham operated group（n =10） and model group（n = 10）. Amplitude of integrated discharges（AID） ,time course of discharges（TCD） and time course of discharge interval（TCDI） were measured as indexes of discharge activity of autonomic nerves. Right atrial appendage samples were obtained and the experssions of TH, ChAT and GAP43 were studied with the immnnofluorescence technique. Results Compared with sham groups, AID of vagus nerve prolonged significantly（P 〈0. 01 ）, but TCD and TCDI did not change in model groups （ P 〉 0. 05 ）. Compared with sham groups, AID of sympathetic nerve decreased significantly in model groups （P 〈 0. 001 ）, and TCD prolonged and TCDI shorted in model groups. The density of TH, ChAT and GAP43 positive nerve fibers were significantly higher in model groups than sham operated groups. Conclusions RAP induces cardiac nerve degenerating, regenerating and remodeling. The finding suggested that autonomic nerve remodeling could maintain developing of atrial fibrillation.