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

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

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。

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.