The Action Of PPARα And CaN On The Exercise Rat Myocardial Micro-injuries And Ventricular Remodeling

Objective:To investigate the changes and the rules of rat myocardial Peroxisome Proliferator-activated Receptor alpha(PPARα),Hypoxia Inducible Factor-1 alpha(HIF-1α) and Calcineurin(CaN) at 0 hour,6 hours,12 hours and 24 hours after exhausted exercises.In order to discuss the mechanism of myocardial function abnormity in the process of both exercise-induced heart micro-injuries and ventricular remodeling.Methods:90 male Sprague-Dawley rats were randomly divided into sedentary control group,single bout of exhausted exercise 4 groups and two weeks consecutive daily exhausted exercise groups,and were killed at different time cases after exhausted exercise.Use immunofluorescence technic and image-analysis method to study the changes of the content of PPARα,HIF-1αand CaN in rats myocardial tissue.Results:1 The content of rat myocardial PPARαreduced after exhausted exercise. The content of PPARαin interventricular and right ventricle at 6 hours after single bout exhausted exercise was remarkable lower than control group(p＜0.01,p＜0.05),and returned to the control group level at 12-24 hours.The interventricular PPARαcontent at 0 hour and 24 hours after consecutive daily exhausted exercises were both remarkable lower than control group(p＜0.01,p＜0.05).The interventricular PPARαcontent at 0 hour and 24 hours after consecutive daily exhaused exercises were remarkable lower than that after single bout exercise(p＜0.05).2 The content of rat myocardial HIF-1αincreased after exhausted exercise.Rat ventricular HIF-1αcontent at 0 hour,6 hours,12 hours after single bout exhausted exercise were all higher than control group(p＜0.05),and returned to the control group level at 24 hours.At the moment after consecutive daily exhaused exercises,left and right ventricular HIF-1αcontent were remarkable higher than control group(p＜0.05),but unconspicuous in interventricular(p＞0.05).3 After single bout exhausted exercise,the change of rat myocardial CaN content wasn't evidence,only that of interventricular at 0 hour after exercise was remarkable higher than control group(p＜0.05).After consecutive daily exhaused exercise,the content of interventricular at each time cases after exercise were remarkable higher than control group(p＜0.05,p＜0.01),and that of left ventricle at 0 hour and of right ventricle at 24 hours after exercise were both higher than control group (p＜0.01,p＜0.05).The CaN content in interventricular and right ventricle at 24 hours after consecutive daily exhaused exercise were remarkable higher than that at 24 hours after single bout exhausted exercise(p＜0.05,p＜0.01).Conclusion:1 After exhausted exercises myocardial PPARαexpression level was related to the resume of anoxemic myocardial energy supply and heart injury grade,it is important mechanism of heart micro-injuries and ventricular remodeling.2 Myocardia responsed to anoxia by HIF-1αcontent increased to aviod myocardia injured badly.But after consecutive daily exhausted exercises the expression of HIF-1αwas restrained,so myocardia injured quite badly.The myocardial HIF-1αexpression after exhausted exercise concerned to adjust exercise-induced heart micro-injuries.3 After single bout exhausted exercise,myocardial CaN expression was not the master conditioner about myocardial anoxic injury.It had more important effect in the course of myocardial cell hypertrophy after consecutive exhausted exercises.The myocardial CaN expression after exhausted exersises was the important mechanism of exercise-induced ventricular remodeling.4 After consecutive exceed load exercise,interventricular injury was most sensitive and worst in heart,in the next was right ventriculia, and left ventriculia injury was gentle comparatively.