左心室肥厚跨室壁缝隙连接蛋白43表达异质性的改变  

The changes of transmural heterogeneity in connexin 43 expression level in the condition of left ventricular hypertrophy

作　　者：钟江华[1,2] 姚震 陈漠水[1,2] 孙定军[1,2] 王柳[1,2] 陆士娟[1,2] 

机构地区：[1]中南大学湘雅医学院附属海口医院 [2]海口市人民医院心血管内科,海南海口570208 [3]三亚市人民医院心血管内科

出　　处：《中华高血压杂志》2013年第6期548-552,共5页Chinese Journal of Hypertension

摘　　要：目的观察高血压左心室肥厚(LVH)跨室壁复极不均一性的改变及三层心肌缝隙连接蛋白43(CX43)分布的异质性,探讨LVH易发恶性室性心律失常(MVA)的电生理和分子机制。方法将家兔20只随机分成LVH实验组和对照组,每组10只,用传统的腹主动脉缩窄术制作LVH模型,检测两组家兔的心室颤动阈值及心外膜下层、中层心肌和心内膜下层心肌细胞的单相动作电位复极90%时程(APD90)、跨室壁复极离散度(TDR)以及CX43蛋白表达。结果与对照组比较,LVH实验组心室颤动阈值降低[(7.50±1.58)比(12.20±1.75)V,P<0.05];中层心肌APD90与心内膜下层心肌APD90之差(ΔAPD90)[(32.40±9.67)比(24.30±5.68)ms]和TDR[(48.90±11.65)比(36.40±7.40)ms]升高(均P<0.05)。与对照组比较,LVH实验组三层心肌的APD90明显延长(均P<0.01),而三层心肌CX43蛋白表达明显下降,中层心肌下降最为明显。结论 LVH跨室壁CX43表达异质性增加,与左心室跨室壁复极不均一性增大,诱发MVA有关。Objective To examine the changes of transmural heterogeneity during ventricular repolarization and heterogeneity of the expression levels of connexin 43 （CX43） protein in three myocardial layers in a rabbit hypertensive left ventricular hypertrophy （LVH） model, and to explore electrophysiological and molecular mechanisms of malignant ventricular arrhythmia （MVA） in the condition of LVH. Methods Twenty rabbits were randomly divided in to LVH group （n = 10 ） , which was established with traditional abdominal aorta constriction and sham operation group （n=10）. In both groups, ventricular fibrillation threshold （VFT）, 90% monophasic action potential repo larization duration （ APD90 ） in subepicardial myocardial, midmyocardial and subendocardial myocardial cells, as well as the transmural dispersion of repolarization （TDR） and the levels of CX43 protein expression in all three layers of myocardium were measured. Results Compared with the sham operation group, in LVH group, VFT were significantly decreased [（7.50±1.58） vs （12. 20±1.75）V, P〈0.05]; the difference in APD90 （ AAPD90 ） between sub epicardial myocardium and midmyocardium [（32.40±9.67） vs （24.30±5.68）ms], and TDR [（48.90±11.65） vs （36.40± 7.40）ms] were significantly increased （all P〈0.05）; while APD90 in three myocardial layers were significantly prolonged （all P±0.01）, CX43 protein expressions in all three myocardial layers were significantly decreased and most significantly in midmyocardium. Conclusion Increased transmural heterogeneity in CX43 expression may induce heterogeneity of repolarization across ventricular wall and result in MVA in LVH.

关 键 词：左心室肥厚 缝隙连接 复极异质性 中层心肌细胞 

分 类 号：R541.3[医药卫生—心血管疾病]