通心络对大鼠心肌梗死后神经重构和室颤阈值的影响

目的探讨通心络(TXL)对大鼠心肌梗死(MI)后神经重构和室颤阈值的影响。方法应用结扎冠状动脉前降支的方法制备大鼠MI模型,将大鼠随机分为3组:假手术组、MI组和TXL组(n=8),第6周应用超声心动图测定心脏结构和功能后进行室颤阈值测定;免疫组化法研究大鼠心室肌中生长相关蛋白43(GAP43)和酪氨酸羟化酶(TH)阳性神经纤维的分布和密度。结果与假手术组相比,MI组心室肌神经分布紊乱,神经纤维密度明显增高(P<0.05),室颤阈值明显降低(P<0.05);TXL组较MI组神经纤维密度明显降低(P<0.05),室颤阈值明显升高(P<0.05),并接近假手术组。结论TXL能改善MI后神经重构反应,提高室颤阈值,有预防MI后室性快速心律失常的潜在作用。

Effects of Tongxinluo on sympathetic remodeling and ventricular fibrillation threshold after myocardial infarction in rats

Objective To study the effects of Tongxinluo(TXL)on sympathetic remodeling and ventricular fibrillation threshold(VFT) after myocardial infarction(MI) in rats. Methods MI was induced by ligation of the left anterior descending coronary arteries in the rats.The rats were then randomized to sham-operated group,MI group and TXL group(n =8).Six weeks after operation,cardiac structure and function were assessed by echocardiography,VFT was then measured,and the distribution and density of growth associated protein 43(GAP43) and tyrosine hydroxylase(TH) in ventricles were detected by immunohistochemistry. Results The distribution of nerve fibers in ventricles of sham-operated group was homogeneous,and became chaotic in MI group.The density of nerve fibers with positive immunostaining for GAP43 and TH significantly increased in MI group compared with that in sham-operated group(P<0.05).VFT was significantly lower in MI group than that in sham-operated group(P<0.05).The nerve fibers density in TXL group was significantly lower than those in MI group(P<0.05).VFT in TXL group significantly increased compared with that in MI group(P<0.05),and was similar to sham-operated group. Conclusion TXL can inhibit sympathetic remodeling,increase VFT after MI in rats,and plays a potential role in the prevention of ventricular tachyarrhythmia after MI.