慢性压力超负荷兔左室心肌细胞电重构与结构重构发生的非同步性  

Asynchronous development of electrical remodeling and structural remodeling in rabbit left ventricle with chronic pressure-overload.

作　　者：赵永辉[1] 崔长琮[2] 顾媛媛[3] 

机构地区：[1]河南省人民医院心内科,河南郑州450003 [2]西安交通大学第一医院心内科,陕西西安710061 [3]郑州市第五人民医院,河南郑州450003

出　　处：《中国心脏起搏与心电生理杂志》2009年第1期59-62,共4页Chinese Journal of Cardiac Pacing and Electrophysiology

摘　　要：目的探讨慢性压力超负荷兔中层心室肌细胞电重构与结构重构发生的非同步性及其意义。方法新西兰兔64只,随机分为缩窄组和假手术组,采用肾上腹主动脉缩窄术制备兔左室压力超负荷模型。术后2周和8周胶原酶两步消化法分离获取左室中层单个心肌细胞,应用激光扫描共聚焦显微镜技术测定中层细胞体积和蛋白含量,全细胞膜片钳技术记录中层细胞膜电容、动作电位(AP)。结果与假手术组比较,术后2周缩窄组中层细胞体积、蛋白含量及膜电容无明显改变,但基础刺激周长(BCL)为2 s时,缩窄组AP复极达90%时程(APD90)较假手术组延长13.7%(P<0.05);与假手术组比较,术后8周缩窄组中层细胞体积、蛋白含量及膜电容分别增加28.0%、38.3%、34.0%(P<0.05或0.01),APD90延长30.6%(P<0.01)。术后2周和8周,与假手术组比较,缩窄组中层细胞APD呈现更明显的频率依赖性,且更易发生早期后除极(BCL=2 s,EAD)。结论左室慢性压力超负荷过程中,中层心肌细胞电重构的发生明显早于结构重构,且可能具有潜在致心律失常危险。Objective To investigate asynchronous development and its significance in electrical remodeling and struc- tural remodeling in rabbit left ventricle with chronic pressure-overload. Methods Sixty-four new Zealand rabbits were randomly divided into constriction group and sham group. The rabbit ventricle models with chronic pressure-overload were prepared by partial constriction of superrenal abdominal aorta. At 2 and 8 weeks after operation, the single myocytes were enzymatically isolated from the midmyocardium in the antelateral free wall of left ventricle. Whole cell patch clamp tech- nique was used to record the membrane capacitance, action potential（AP） of the single midmycardial （M）ceils. The vol- ume and protein content of M cells were measured by confocal laser scanning microscope analysis. Results At 2 weeks after operation, compared with sham group, the volume , protein content and membrane capacitance of M cells from con- striction group had no changes, however, at basic cycle length （BCL） of 2 s, the AP duration at 90% repolarization （ APD90 ） of M ceils in constriction group was 13.7% longer than that in sham group（P 〈 0.05 ）. At 8 weeks after operation, compared with sham group, the volume, protein content and membrane capacitance of M ceils from constriction group significantly increased by 28.0% ,38.3% ,34.0% （P 〈0.05 or O. 01 ）, respectively. At BCL of 2 s, APD90 of M cells in constriction group was 30.6% longer than that in sham group（ P 〈 0.0l ）. At 2 and 8 weeks after operation, compared with sham group, APD of M ceils in constriction group presented more pronounced slow frequency-dependence and were easier to produce early afterdepolariztion（EAD）. Conclusion During the chronic pressure-overload, electrical remodeling of M cells from left ventricle precedes structural remodeling, which could be a risk factor for the occurrence of arrhythmia. [ Chinese Journal of Cardiac Pacing and Electrophysiology ,2009,23 （ 1 ） ：59 - 62 ]

关 键 词：电生理学 电重构 结构重构 慢性压力超负荷 

分 类 号：R331.38[医药卫生—人体生理学]