慢性肾脏病兔心肌跨壁复极离散及膜离子流变化的实验研究  

Experimental study on the dispersion of myocardial transmural repolarization and the changes of membrane ion current in rabbits with chronic kidney diseases

作　　者：余平[1] 李晴[2] YU Ping;LI Qing(Dept.of Emergency,Wuhan Third Hospital&Tongren Hospital of Wuhan University,Wuhan 430060,Hubei,China;Dept.of Cardiopulmonary Function,Wuhan Third Hospital&Tongren Hospital of Wuhan University,Wuhan 430060,Hubei,China)

机构地区：[1]武汉市第三医院/武汉大学附属同仁医院急诊科,湖北武汉430060 [2]武汉市第三医院/武汉大学附属同仁医院心肺功能科,湖北武汉430060

出　　处：《武汉大学学报（医学版）》2022年第3期370-375,共6页Medical Journal of Wuhan University

基　　金：武汉市卫生和计划生育委员会资助项目(编号:WX18D47)。

摘　　要：目的:分析讨论慢性肾脏病(CKD)心肌跨壁复极离散与心电表现以及膜离子流变化的特征及相互关联。方法:进行实验动物心室肌细胞的分离与复钙,观察不同时期、不同部位心肌病理特征,进行心电图测定,借助单相动作电位记录技术分析心肌单相动作电位,使用膜片钳技术观察电解质干预下膜离子流变化。分析慢性肾脏病心肌跨壁复极离散与心电表现以及膜离子流变化的特征及相互关联。结果:HE染色后CKD组与对照组实验动物心肌病理特征区别明显;同时CKD组T波振幅总水平低于对照组水平;CKD组Tp-Te以及Tp-Ted总水平均高于对照组(均P<0.05)。CKD组内不同病期对比,1~4期T波振幅高于5期水平,Tp-Te以及Tp-Ted均低于5期水平(均P<0.05)。不同心肌细胞静息膜电位(RMP)、最大动作电位幅度(APA)和动作电位复极90%时程(APD_(90))基础值差别未见统计学意义。随着时间点变化,CKD组及对照组的外膜层心肌细胞RMP、APA和APD_(90)变化趋势可见逐渐表现更低或先升高后减低的不同。并且,本研究中浸浴液K^(+)浓度为75 mmol/L和145 mmol/L,实验条件下达到钾的平衡电位;当膜电位高于此平衡电位后,电流可见转成外向,但幅值很小;继续增大膜电位后,电流幅值并不继续增大。进一步观察到,细胞内Mg^(2+)浓度对内向整流作用的影响:在无Mg^(2+)浸浴液的条件下,I-V曲线呈一准曲线,表明内向整流作用不明显。当浸浴液含1 mmol/L Mg^(2+)时,内向电流无影响,而外向电流受到明显抑制,从而出现明显内向整流特点,当移去细胞内Mg^(2+)时内向整流特性几乎完全消失。结论:CKD兔心肌跨壁复极离散的变化对心电图T波的形态有重要影响;希望基于此可以为临床医师在CKD心血管病变病程评估、疗效判断方面提供一种更为简便、可行、无创的辅助检查方法。Objective:To analyze and discuss the characteristics and interrelationship between the dispersion of transmural repolarization of myocardium,electrocardiogram,and changes in membrane ion current in experimental animals with chronic kidney diseases(CKD).Methods:The separation and recalcification of ventricular myocytes in experimental animals were carried out.The pathological observations of myocardium in different periods and different parts were observed.The electrocardiogram was measured.The single-phase action potential of the myocardium was analyzed by the single-phase action potential recording technique.The patch clamp technique was used to observe the membrane ion flow changes under electrolyte intervention.The characteristics of the dispersion of myocardial repolarization across the wall,the electrocardiogram performance,and the changes of membrane ion current were analyzed.Results:In the study,the myocardial pathological characteristics of the experimental animals in the CKD group and the control group were significantly different after HE staining.The total level of T wave amplitude in the CKD group was lower than that in the control group while the total levels of Tp-Te and Tp-Ted in the CKD group were higher(all P<0.05).Among different disease stages in the CKD group,the T wave amplitude of stages 1-4 was higher than that of stage 5,and both Tp-Te and Tp-Ted levels of stages 1-4 were lower than those of stage 5(all P<0.05).No difference was found in the baseline values of cardiomyocytes RMP,APA,and APD_(90)between control and CKD groups.But after electrolyte intervention,the changes of RMP,APA and APD_(90)of the CKD group were different from that of the control group.Moreover,when the K^(+) concentration of the immersion bath was 75 mmol/L and 145 mmol/L,and the equilibrium potential of potassium was reached under the experimental conditions;when the membrane potential was higher than this equilibrium potential,outward current could be found,but its amplitude was small;After continuing to increase the

关 键 词：慢性肾脏病 心肌跨壁复极离散 膜离子流 心电图 

分 类 号：R331.38[医药卫生—人体生理学] R540.41[医药卫生—基础医学]