Protection Effect and Its Mechanism of Exercise Preconditioning on Myocardial Iniury-Induced by Heavy Load Treadmill Training in Rat

Objective:To make clear the basic characteristics of myocardial iniury-induced by heavy load training,and explore the protective effect and its mechanism of exercise preconditioning(EP) on it.Methods:Sixty-four grown male SD rats were randomly divided into control group(group AB),exercise preconditioning control group(group AC),heavy load training group,heavy load training after exercise preconditioning group(group C).According to instantly,6 hour and 24 hour after heavy load training,group B were randomly divided into group B1,group B2,group B3 and group C were randomly divided into group C1,group C2,group C3.Rats in group AC,group C had took part in medium load treadmill training for 6 weeks.Rats in group C took part in a heavy load treadmill training at 48 hour after medium load treadmill training with group B.All groups index of serum cardiac troponin-I(cTnI),creatine kinase rsoenzyme(CK-MB),and cardiac superoxide dismutase(SOD),malondialdehyde(MDA) and Ca2+ were be test.High performance liquid chromatography(HPLC)text adenosine triphosphate(ATP).Myocardial cellular membrane Na+-K+-ATPase,Ca2+-ATPase activity were also be test.Results:Heavy load training caused serum cTnI and CK-MB concentration were significant higher,and caused cardiac SOD activity was significant lower,cardiac MDA quantitative,Ca2+ concentration were significant higher,ATP quantitative was significant higher,myocardial cellular membrane Na+-K+-ATPase,Ca2+-ATPase activity were significant lower.Conclusion:EP has protective effect on myocardial iniury induced by heavy load training.Higher SOD activity induced by EP causes chain reaction after heavy load training,therefore play against myocardial iniury.