慢性心房颤动犬心房组织肾素-血管紧张素系统的表达及意义

目的探讨肾素-血管紧张素系统(RAS)在慢性心房颤动犬心房组织中的表达及意义。方法健康杂种犬16条,随机分为正常对照组8条,单纯心房颤动起搏组8条。心房颤动组植入埋藏式高频率心脏起博器(500±20)次/min,起博24周后处死动物,分别于左、右心房取材,采用免疫组织化学检测心房组织中肾素-血管紧张素转化酶(ACE)、血管紧张素Ⅱ1型受体(AT1R)以及肾素-血管紧张素转化酶抑制剂(ACEI)的表达变化。正常对照组未植入起搏器,与心房颤动组同步行相应检查。结果与对照组比较,心房颤动组心房组织中ACE和AT1R表达水平显著增强,而ACEI的表达水平明显下降,各组间比较差异有统计学意义(P<0.01)。结论慢性心房颤动犬心房组织RAS的激活参与了心房颤动的形成,可能是心房颤动发生、发展的主要机制之一。

A study on expression of renin angiotensin system in dog atrial during chronic atrial fibrillation

Objective To investigate the expression of renin angiotensin system and its role in atrial tissues of dogs with chronic atrial fibrillation （AF）. Methods Sixteen mongrel dogs were randomly divided into two groups： pacing group（n=8） and control group （n=8）. High frequency pacing （500±20ppm） with a permanent pacemaker was given to the pacing group but not to the control group. After pacing for 24 weeks,the dogs were sacrificed and harvested for tissue samples from the left and right atria. The level of angiotensin-converting enzyme（ACE）, angiotensin Ⅱ type 1 receptors （ATIR） and angiotensin-converting-enzyme inhibitors （ACEI） in atrial tissue were detected by immunohistochemistry. Results Compared with the control group, the expression levels of ACE and ATlR were significantly enhanced （P〈0.01） in atrial tissues during AF, but the expression level of ACEI was obviously decreased （P〈0.01）. Conclusion Activation of renin angiotensin system （RAS） may be involve in development of atrial fibrillation,and may be one of mechanisms underlying this condition.