力竭游泳后大鼠心肌基质金属蛋白酶活性的变化及其与心功能的关系

Changes of myocardial matrix metalloproteinases activities in rats after exhausted exercise and their relationship with cardiac function

目的探讨力竭游泳后大鼠心肌基质金属蛋白酶(MMPs)活性的变化及其与运动性心肌重建和心功能异常的关系。方法建立一次性力竭游泳大鼠模型,通过胸超声心动图检测大鼠力竭游泳后即刻、3、6、12、24 h的心功能,包括主动脉血流峰值流速(PFVA)、主动脉血流速度积分(Viao)、左心室舒张末期直径(LVEDD)和左心室收缩末期直径(LVESD),并计算左室射血分数(LVEF)和左室短轴缩短率(LVFS);采用RT-PCR方法检测心肌MMP-1和MMP-9的mRNA含城,酶谱法分析心肌MMP-1和MMP-9活性;分析MMP-1和MMP-9活性变化与心功能指标之间的相关关系。结果力竭游泳后大鼠心肌MMP-1和MMP-9的mRNA含量水平显著高于对照组(P<0.01),MMP-1和MMP-9活性比对照组明显增加(P<0.01);与对照组比较,力竭游泳后大鼠PFVA、Viao、LVEF和LVFS显著减少(P<0.01);MMP-1和MMP-9 mRNA水平与PFVA、Viao、LVEF和LVFS呈负相关(P<0.05)。结论力竭游泳引起大鼠心肌MMPs的过度表达,并引起运动性心肌重建和心功能异常,研究提示,力竭游泳后大鼠心肌MMPs的过度表达可能与运动性心肌重建和心功能异常有关。

Objective To investigate the changes of myocardial matrix metalloproteinases(MMP)activities in rats after exhausted exercise and their relationship with exercise-induced cardidc remodeling and cardiac function.Methods The cardiac function indexes of rats such as peak flow velocity of aorta(PFVA),flow velocity integral of aorta(Viao),left ventricular cnd-diadtolic internal diameter(LVEDD),and left ventricular end-systolic internal diameter(LVESD) were determined by echocardiography at 0,3,6,12,24 hours after exhausted exercise.The left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS) were calculated.MMP-1 and MMP-9 mRNA contains were measured with RT-PCR method,while MMP-1 and MMP-9activities were measured with SDS-PAGE type substrate gels embedded with type gelatin.Their relationship with cardiac function was analyzed.Results In exhausted exercise rats,both MMP-1 and MMP-9 mRNA contains and activities were increased significantly compared with those in controls(P <0.01),and the PFVA,Viao,LVEF and LVFS were reduced significantly compared with those in controls(P <0.01).Both MMP-1 and MMP-9 mRNA contains and activities were negatively correlated with PFVA,Viao,LVEF and LVFS(P <0.01).Conclusion The exerciseinduced cardiac remodeling and cardiac dysfunction induced by exhausted exercise may relate with over expression of MMP-1 and MMP-9.