The Effcet Of Different Load-bearing Trainning On Apoptosis And Bcl-2,Bax Expression In Aged Cardiac Muscle Of Rats

Destination: Through researching on the affection about the programmed cell deathand the expression change of the related gene Bcl-2 and Bax, in order to found the generalregulation about them. Then we can establish rational exercise load and offer theory for thetraining.Method: Produce 32 male Wistar rats aged at 17-months were separated randomly intosedentary control group(group A),middle load exercise group(group B),high load exercisegroup(group C),and every group had 8 rats.(1)Group A was bred normal without anyexercise;(2) Group B,Group C,Group D were respectively burdened with 30%,50% and60% the weights of their maxi-mum loads. For the exercise training groups they wereexerted interval run training on tread-mill with the above burdens separately for 8 weeks.One set of training consisted of running 2minutes and resting 2 minutes and 6 sets of thiscontinuous training were exerted, one time for every day and 6 times for every week withSunday resting. All the rats were weighed one time a week, their hair color and mentalstatus were observed every day. After 8weeks, exercise training was stopped and all ratswere killed the next day. The changes of HE,apoptosis,Bcl-2 expression,Bax expressioncontent in left ventricular muscle were observed. Then analyze the otherness and therelativity of the indexes of the different load exercises.Result: The left ventricular muscle fibers of group D hypertrophy, and had nothingdistinctnecrotic cell death. Every group had apoptotic cells, but. Apoptotic index of group Awas higher significantly than group B,C,D(P<0.01). Every group had Bcl-2expression.Bcl-2 expression of group B,C,D were higher than group A .Group C ashigher significantly than group A(P<0.01).Group B,D were higher than groupA(P<0.05)and lower than group C(P<0.05). Bax activity of group C was lower than groupA,B,D(P<0.05).Conclusions: Different Load-bearing Trainning results in different changes on bothstructure and apoptosis. High load exercise does harm to the myocardial cell.Comparedwith the middle load exercise group, the apoptotic index was increased apparently. The increase of apoptosis cardiac myocyte might be the pathological and physiologicalmechanism for lowering cardiovascular function after high load exercise. After high loadexercise the decrease of Bcl-2 expression of cardiac myocyte maybe one of the mechanismof genetic controls on apoptosis in cardiac muscle cell. Middle load exercise could causethe Bax protein positive expression but high load exercise increase the decrease of thepositive expression of Bax protein, which might also be one of the mechanisms forregulating the apoptosis of cardiac muscle cell.