钙激活蛋白酶系统与慢性房颤犬心房重构关系的研究  

Effects of the calpain system expression on atrial structural remodeling in canine with atrial fibrillation

作　　者：马骁[1] 张薇[1] 钟明[1] 黎莉[1] 苗雅[1] 孙慧[1] 张运[1] 

机构地区：[1]教育部和卫生部心血管重构和功能研究重点实验室

出　　处：《中国病理生理杂志》2007年第10期1883-1886,共4页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.30370564)

摘　　要：目的:探讨慢性房颤犬心房肌钙激活蛋白酶(calpain)系统表达水平的改变及其与心房重构的相关性。方法:17只杂种犬随机分为心房颤动组(11只)和对照组(6只),于起搏前后均进行经胸超声心动图检查,测量舒张期左房内径。房颤组经颈外静脉将电极置入右心耳快速起搏(400 beats/min)8周复制房颤模型,开胸取心房组织,测定心房肌Ca2+浓度,用荧光实时定量PCR和Western blotting技术检测calpain及其抑制剂calpastatinmRNA和蛋白的表达量。结果:房颤组心房肌Ca2+浓度升高,左房内径显著大于起搏前及对照组(P<0.05),房颤组和对照组比较犬心房肌calpainⅠ、calpainⅡmRNA表达无显著差异(P>0.05),房颤组calpastatin mRNA表达明显高于对照组(P<0.05);房颤组calpainⅠ、calpainⅡ蛋白表达明显高于对照组(P<0.05),calpastatin蛋白表达明显低于对照组(P<0.05)。CalpainⅠ、calpainⅡ蛋白表达水平与左房内径呈显著正相关(r=0.53,r=0.67,P<0.05),calpastatin蛋白表达水平与左房内径呈显著负相关(r=-0.74,P<0.05)。结论:房颤所引起calpain系统的蛋白表达改变,使calpain/calpastatin系统相互间作用失衡,造成多种蛋白被降解可能是心房重构的重要机制。AIM： To evaluate the influence of the ealpain system mRNA and protein expression on the progress of atrial structural remodeling in fibrillating canine. METHODS： 17 dogs were randomly divided into 2 groups： normal control group （ SR, n = 6） and atrial fibrillation （ AF, n = 11 ） group. AF was induced by rapid pacing for 8 weeks and all dogs underwent transthoratic echocardiography before and after rapid pacing. The mRNA and protein expression of calpain Ⅰ , calpain Ⅱ and calpastatin were assessed by real -time quantitative PCR and Western blotting, respectively. RFSULTS： Compared with SR group, the left atrial diameters and the content of calcium in atrial myocardium increased significantly in AF group （P 〈0. 05）. There was no significant difference in mRNA expression of calpain Ⅰ and calpain Ⅱ （P 〉 0. 05 ） between two groups. The expression of calpastatin mRNA was upregulated significantly in AF group （ P 〈 0. 05 ）. The levels of calpain Ⅰ and calpain Ⅱ protein were significantly increased in AF group compared with SR group （P 〈 0. 05）. The expression of calpastatin protein was significantly decreased in AF group （P 〈 0. 05 ）. The calpain Ⅰ and calpain Ⅱ protein levels were positively correlated with the left atrial diameter. The calpastatin protein level was negatively correlated with the left atrial diameter （P 〈 0. 05）. CONCLUSION： The changes of the calpain system protein expression in AF result in the disturbance of calpain/calpastatin system and degradation of many proteins, which may play an important role in mecha- nism of atrial remodeling.

关 键 词：心房颤动 卡配因 犬 

分 类 号：R363[医药卫生—病理学]