卡维地洛对扩张型心肌病交感神经分布和室颤阈值的影响

Effect of Carvedilol on Sympathetic Innervation and Ventricular Fibrillation Threshold in Rabbit Models with Dilated Cardiomyopathy

目的 观察卡维地洛对家兔扩张型心肌病交感神经分布和室颤阈值的作用。方法 将家兔随机分为扩张型心肌病组、卡维地洛组和正常对照组。阿霉素静脉注射 8周造成扩张型心肌病模型 ,卡维地洛组给予口服卡维地洛 8周进行干预。体内用非程序刺激方法测定室颤阈值 ,体外对 3组家兔心脏进行病理分析并用免疫组化技术检测交感神经分布。结果 扩张型心肌病组和卡维地洛组较正常对照组各心腔明显增大、室壁变薄、交感神经数量显著增多。扩张型心肌病组室颤阈值较卡维地洛组和正常对照组明显降低 (P <0 0 1) ,但卡维地洛组交感神经分布与扩张型心肌病组相比无明显差异。结论 卡维地洛能提高扩张型心肌病室颤阈值 ,对交感神经分布无明显影响。

Objective To observe the effect of carvedilol on sympathetic innervation and ventricular fibrillation threshold in rabbit models with dilated cardiomyopathy (DCM). Methods All rabbits were randomly divided into DCM, carvedilol and control groups. Doxorubicin was intravenously injected for 8 weeks to establish the rabbit models of DCM, and in carvedilol groups the rabbits were administrated with oral carvedilol for 8 weeks. Ventricular fibrillation threshold was detected in vivo with nonprogrammed stimulation technique. The rabbit hearts in the 3 groups were pathologically analyzed and sympathetic innervations were detected in vitro by immunohistochemistry technique. Results In comparison with control groups, cardiac chamber volume and sympathetic nerves were increased significantly, while ventricular wall thickness were decreased significantly in DCM groups and carvedilol groups as compared with control group. The ventricular fibrillation thresholds in DCM group were reduced significantly as compared with carvedilol group and control group (P<0.01), but there was no significant difference in sympathetic innervation between DCM group and carvedilol group. Conclusion Carvedilol can increase ventricular fibrillation threshold in rabbit with DCM, but doesn't influence sympathetic innervation significantly.