The Influence Of Exercise On Heat Shock Protein 70 Expression Of Cardiocyte In Rats

Objective:Heat shock protein 70(HSP70) can protect organization against injuries. Some researchers recently reported that exercise was a factor that can induce HSP70 expression.So, we produced aerobic exercise and overload exercise model of rats in order to see the influence of exercise on the myocardial HSP70 expression, find the relationship between the injury of cardiocyte and the expression of HSP70,and explore the regulation of HSP70 expression in cardiocyte after exercises. It will provide theoretical evidence and guidance to research the athlete's heart and the prevention of sudden death.Method:Twenty-four male Sprague-Dawley (SD) rats were randomly separated into aerobic exercise group (swimmed 75min every day without any load); overload exercise group (swimmed 180min with 5% weight of its body every day); control group (without any exercise). They swimmed 16 weeks.They were killed after 24 hours of last exercise. The change of cardiocyte was viewed by HE dyeing.The expression of HSP70 was detected by immunohistochemistry stain.Using Image-Pro Plus5.1 pictures analyze system measured the value of integral optical density(IOD) of HSP70 expression.The datum were analysed by SPSS 11.0.Results and analyse:1. IOD units of HSP70 expression in the aerobic exercise group and overload exercise group was 2837.93±2060.57 and 4682.56±2750.85,respectively. There was significance difference among the three group(P<0.01,P<0.05). 2. Cardiocyte hadn't abnormal change in control group. The cardiocyte in aerobic exercise group and overload exercise group became bigger than that in control group. However, compared with control group and aerobic exercise group, the arrangement of cardiocyte in overload exercise group was disorderly. The cleft between cardiocyte enlarged.The boundary between cells was misty. A part of cardiocyte was fragmentation. We also observed some red blood cells around the cardiocyte in overload exercise group.Conclusion:1. Exercise could induce HSP70 expression in cardiocyte. The expression of HSP70 was related to the exercise load.With the increasing of exercise load, the expression of HSP70 had upward trend. 2. HSP70 played a limited role in protecting cardiocyte against injury.