Study On The Changes Of Myocardial Cell Damage And Autophagy In The Process Of Continuous Aerobic Exercise In Rats

Purpose: This study planned to train rats with long-term intensive aerobic swimming exercise.Observing the myocardium cell morphology,the content of CK-MB and cTnI and the dynamic changes of influence the myocardium cell autophagy relevant LC3`s distribution and expression.Investigating the dynamic changes of CK-MB,cTnI and LC3 during fatigue accumulation process and under over fatigue situation and offering reference of the point of aerobic training cycle,it serve for theory and practice of sports training and physical training.Methods: Male SD rates 84 is randomly divided into 12 groups each has 7 and one as blank control,blank control group normally feed in cages and not participate swimming training,the other rats were trained in two stages.The first stage:according to the rat aerobic swimming model established by Zhang Lingji,established a 7-day fatigue model.the second stage: 7 rats randomly were used as model blank control group.It did not swimming during the entire experimental as M.The rest of the groups were trained immediately after modeling swimming training,one group of rats was randomly killed and taken as a model positive control group(S).After fatigue modeling,each group performed exercise intervention at intervals of 60 hours.And randomly kill one group of rats after every2×60h training and signed as A,B,C,D,E......(n=7),Until all rats are drawn.Results: 1.Except for group N,there were pathological changes in the morphological structure of myocardial tissue in other experimental groups.And it shows that the trend of increasing pathological changes with the fatigue deepen.2.The serum levels of CK-MB in the D,H,I groups were higher than the blank group(N)and it has significant difference(p<0.05).3.The serum cTnI levels in the D,F,G,H,I groups were higher than the blank group(N)and it has significant differences(p<0.05).The serum levels of CK-MB in the S,A,B,C,and E groups are significantly higher than the blank group(N)and it has Significant difference(p<0.01).4.LC3-II/LC-I in group B,C and E increased compared with blank group(N)and it has significant difference(p<0.05).LC3-II/LC-I in group D was significantly increaser than the blank control group(N)and it has significant difference(p<0.01),LC3-II/LC-I in the S group is significantly lower than the blank group(N)and it has significant difference(p<0.01),Concludes:(1)Under this experimental condition,rats weight-bearing continuous swimming cause fatigue in the process,the longer the training time,the heavier the pathological structure changes.And during the fifth week of training,Myocardial fibers appear to be clearly broken.Tip: It may be the critical point of training and fatigue.(2)Under this experimental condition,The decrease of serum CK-MB and cTnI levels may be related to the increased degree of autophagy in cardiomyocytes.Tip: A large amount of aerobic exercisearound four weeks in a row can cause good adaptive remodeling of myocardial tissue cells.The degree of myocardial damage is improved by increasing the level of cellular autophagy.(3)Under this experimental condition,Through the joint analysis of the rising trend of CK-MB and cTnI and the decreasing trend of autophagy,It is thought that the D group(12 x 60 h,5th week)may be the time-point at which the balance between the damage stimulus and the myocardial resilience of the rat is broken.