早期运动锻炼对大鼠急性心肌梗死后心肌组织中细胞因子、血浆脑钠肽及心功能的影响

目的探讨早期运动锻炼对大鼠急性心肌梗死（acute myocardial infarction,AMI）后心肌组织中细胞因子[肿瘤坏死因子α（tumor necrosis factor-α,TNF-α）、白细胞介素10（interleukin-10,IL-10）]、血浆脑钠肽（brain natri-uretic peptide,BNP）以及心功能的影响。方法利用结扎大鼠冠状动脉左前降支,制作大鼠AMI模型。于1周后将存活的21只大鼠按随机数字表法分为2组：耐力运动组11只和对照组10只。另设假手术组10只。耐力运动组行游泳锻炼4周。4周后运用超声心动图检测各组大鼠心功能[左室舒张末期内径（LVEDd）、左室射血分数（LVEF）和短轴缩短率（FS）],并检测心肌组织上清液中TNF-αI、L-10及血浆BNP水平。结果与假手术组比较,耐力运动组和对照组心肌组织上清液中TNF-α、TNF-α/IL-10及血浆BNP水平均明显上升（均P〈0.05）,LVEDd均明显升高（均P〈0.05）、LVEF和FS均明显下降（均P〈0.05）。耐力运动组心肌组织上清液中TNF-α、TNF-α/IL-10和血浆BNP水平及LVEDd均较对照组明显下降（均P〈0.05）,LVEF、FS均较对照组明显升高（均P〈0.05）。耐力运动组血浆BNP水平与LVEF呈负相关（r=-0.928,P〈0.05）,耐力运动组血浆BNP水平与心肌组织上清液中TNF-α水平呈正相关（r=0.868,P〈0.05）。结论早期运动锻炼对AMI大鼠具有心脏保护作用,其保护作用的机制之一可能是下调致炎因子/抗炎因子比例,改善心肌重塑。

Effect of Early Endurance Exercise on Myocardial Cytokines, Plasma BNP and Cardiac Function in Rats after Acute Myocardial Infarction

Objective To investigate the effect of early endurance exercise on the expression of pro-inflammatory cytokine tumor necrosis factor-α（TNF-α） and anti-inflammatory cytokine interleukin-10（IL-10）,plasma brain natriuretic peptide（BNP） levels,and cardiac function in rats with acute myocardial infarction（AMI）.Methods AMI was induced in rats by left anterior descending branch ligation.After 1 week,21 surviving rats with AMI were randomly divided into exercise group（11 rats） and control group（10 rats）.Another group of 10 rats were sham-operated.Rats in exercise group were submitted to swim for 4 weeks.At the end of exercise,left ventricular end diastolic diameter（LVEDd）,left ventricular ejection fraction（LVEF） and fraction shortening（FS） were detected by echocardiography.The levels of TNF-α and IL-10 in the supernatant of myocardial tissue and the levels of plasma BNP were also measured.Results Compared with sham-operated group,the levels of TNF-α,TNF-α/IL-10 in myocardial tissue supernatant,the levels of plasma BNP,and LVEDd in exercise group and control group increased significantly（P0.05）,but LVEF and FS decreased obviously（P0.05）.Compared with control group,the levels of TNF-α,TNF-α/IL-10,the levels of plasma BNP and LVEDd in exercise group decreased significantly（P0.05）,but LVEF and FS increase obviously（P0.05）.In exercise group,the levels of plasma BNP was negatively correlated with LVEF（r=-0.928,P0.05） and positively correlated with TNF-α content（r=0.868,P0.05）.Conclusion Early endurance exercise exerts cardiac protective effect in rats with AMI,and the effect may be mediated by a mechanism involving a decrease in TNF-α/IL-10 ratio and the improvement of ventricular remodeling.