Apelin-13对大鼠缺血心室肌细胞瞬时钠电流的影响

发布时间：2019-01-16 04:27

【摘要】：目的:观察apelin对正常和缺血心室肌细胞瞬时钠电流(INa)的影响以及其对室性心律失常和心脏功能的影响。方法:应用Landgendorff逆灌流系统酶解分离大鼠左室心肌细胞,采用全细胞膜片钳技术观察大鼠左室心肌细胞INa,通过改变电极外液的方法来模拟正常/缺血细胞状态,分正常组(N组)、正常apelin组(N+A组)、缺血组(I组)和缺血apelin组(I+A组)(各组n=10),分别观察apelin-13对正常/模拟缺血心室肌细胞INa的影响;另建立Langendorff灌流离体缺血大鼠心脏模型分为4组(各组n=4):N组、N+A组、I组、I+A组,观察ape-lin-13对各组大鼠离体灌流心脏模型心功能和室性心律失常的影响。结果:Apelin-13(100 nmol/L)在N+A组和I+A组均能增加INa幅度,I-V曲线分析显示N+A组比N组INa幅度增大32%[(-86±13)pA/pF],I+A组比I组INa幅度增大18%[(-52±15)pA/pF];然而I-V曲线分析Apelin-13并未改变最大传导速度,N、N+A、I和I+A组分别为(3.2±0.2)pS/pF、(3.1±0.3)pS/pF、(2.9±0.1)pS/pF和(2.8±0.4)pS/pF(P0.05);各组的半激活电压(V1/2)分别为(-21.9±0.6)mV、(-28.7±0.3)mV、(-30.5±0.7)mV和(-36.8±0.2)mV;Boltzmann曲线各组斜率分别为5.6±0.3、5.1±0.4、4.3±0.3和4.9±0.6(P0.05);V1/2值N+A组比N组改变(-5.9±0.8)mV,I+A组V1/2比I组改变(-7.7±1.3)mV(P0.05)。室性心律失常开始时间、室性心动过速持续时间、心室颤动持续时间及心律失常评分情况,N+A组与N组比较、I+A组与I组比较差异无统计学意义(P0.05);N+A组LVEDP低于N组,LVDP高于N组,dp/dtmax和dp/dtmin高于N组;I+A组LVEDP低于I组,LVDP高于I组,dp/dtmax和dp/dtmin高于I组;以β-肌动蛋白(β-actin)作为内参照,4组β-actin表达水平差异无统计学意义,4组Na+通道蛋白Vα亚单位的表达灰度值分别为28.8±3.6、29.4±4.1、30.1±2.9和31.3±3.8,组间差异无统计学意义。结论:Apelin-13可能是通过改变Na+通道门控特性增加INa峰值,使正常和缺血组心室肌细胞Na+通道更容易开放。Apelin-13对缺血相关室性心律失常无影响,对正常和缺血心肌均有正性肌力作用。
[Abstract]:Aim: to observe the effects of apelin on transient sodium current (INa) and ventricular arrhythmia and cardiac function in normal and ischemic ventricular myocytes. Methods: rat left ventricular cardiomyocytes were isolated by enzymatic hydrolysis with Landgendorff reverse perfusion system. The INa, of rat left ventricular cardiomyocytes was observed by using whole-cell patch clamp technique to simulate the normal / ischemic cells by changing the extracellular solution. Normal group (N group), normal apelin group (N A group), ischemic group (group I) and ischemic apelin group (I A group) (n = 10). The effects of apelin-13 on INa of normal / simulated ischemic ventricular myocytes were observed. In addition, the Langendorff perfused isolated ischemic rat heart model was divided into four groups:, N A group (, N A group) and, I A group (group I). The effects of ape-lin-13 on cardiac function and ventricular arrhythmia in isolated perfused rat heart were observed. Results: Apelin-13 (100 nmol/L) could increase the amplitude of INa in both group A and group I. I-V curve analysis showed that the amplitude of INa in group A was 32% higher than that in group N [(-86 卤13) pA/pF]. The amplitude of INa in group I and A was increased by 18% [(-52 卤15) pA/pF]. However, I-V curve analysis of Apelin-13 did not change the maximum conduction velocity, and the values of NAA I and I A groups were (3.2 卤0.2) pS/pF, and (3.1 卤0.3) pS/pF, respectively. (2.9 卤0.1) pS/pF and (2.8 卤0.4) pS/pF (P0.05); The half activation voltage (V 1 / 2) of each group was (-21.9 卤0.6) mV, (-28.7 卤0.3) mV, (-30.5 卤0.7) mV and (-36.8 卤0.2) mV;, respectively. The slope of Boltzmann curve in each group was 5.6 卤0.3 and 4.9 卤0.6 respectively (P 0.05). V1 / 2 value in group A was significantly higher than that in group N (-5.9 卤0. 8). The change of V1 / 2 in group A was higher than that in group I (-7.7 卤1.3) mV (P 0.05). The onset time of ventricular arrhythmia, the duration of ventricular tachycardia, the duration of ventricular fibrillation and the score of arrhythmias were not significantly different between, N A group and N group compared with, I A group and I group (P0.05). The LVEDP of group A was lower than that of group N, LVDP was higher than that of group N, dp/dtmax and dp/dtmin were higher than group I, LVEDP of group; I A was lower than group I, LVDP was higher than group I, dp/dtmax and dp/dtmin were higher than group I. Using 尾 -actin (尾-actin) as internal control, there was no significant difference in the expression of 尾-actin among the four groups. The gray levels of V 伪 subunit of Na channel protein in the four groups were 28.8 卤3.6 卤29.4 卤4.1 卤30.1 卤2.9 and 31.3 卤3.8, respectively. There was no significant difference between groups. Conclusion: Apelin-13 may increase the peak value of INa by changing the gated characteristics of Na channels, which makes it easier to open the Na channels in ventricular myocytes of normal and ischemic groups. Apelin-13 has no effect on ischemic ventricular arrhythmias. It has positive inotropic effect on both normal and ischemic myocardium.
【作者单位】：天津医科大学;天津医科大学总医院;
【分类号】：R363

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