急性心肌缺血再灌注HSP70及c-Fos的免疫组织化学研究

Immunohistochemical study of Fos and HSP70 proteins on the acute myocardial ischemia/reperfusion in rats

运用免疫组织化学方法 ,观察心肌缺血后不同时间再灌注HSP70及Fos蛋白在心肌组织不同区域表达的规律 ,为心肌缺血 /再灌注损伤所致心性猝死的法医学诊断提供形态学依据。结扎大鼠左冠状动脉前降支建立急性心肌缺血 /再灌注模型 ,取缺血区域 (左冠脉前降支供血区 )及非缺血区 (右心室 )心肌组织。结果显示 :对照组正常心肌组织无Fos蛋白及HSP70表达。Fos蛋白在心肌缺血 15min再灌注 0 5h后即在缺血区域表达 ,随着再灌注时间延长其表达增强 ;非缺血区域 1h始有表达 ,缺血区域表达明显强于非缺血区域。HSP70在心肌缺血区域再灌注 1h后始有表达 ,随着再灌注时间延长其表达增强 ;非缺血区域心肌 2h始有表达 ,且明显弱于缺血区域。同时发现再灌注早期HSP70及Fos均先于心肌内层表达 ,随着时间延长其表达向心肌外层扩展。Fos在再灌注 0 5h时主要在心肌内层表达 ,1h时已扩展到心肌全层 ,4h时其心肌外层表达明显强于心肌内层。HSP70在再灌注 1、 2h时主要在心肌内层表达 ,4、 6h时表达扩展至全层心肌。心肌缺血 /再灌注早期不同时间HSP70及Fos表达有不同的区域性及强度 ,此可为心肌缺血

To study the expression of both Fos and HSP70 proteins in the early stage of acute myocardial ischemia/reperfusion(I/R) in rats with immunohistochemistry in order to search the objective morphologic evidence for the forensic pathological diagnosis.I/R rat model was established by ligation of the anterior branch of the left coronary artery.All animals were divided into 7 groups.Tissues were cut and stained immunohistochemistry with the corresponding anti Fos and anti HSP70 sera as the first antibodies.There was no expression of both Fos and HSP70 proteins in control group.The expression of HSP70 protein began to increase in myocytes 1h after I/R in the ischemic areas and increased gradually wtih the prolongation of ischemia,while it began to express 2h after I/R in the non ischemic areas.Fos protein began to express 0 5h after I/R in the ischemic areas,1h in the non ischemic areas.The expressions of both HSP70 and Fos proteins in the non ischemic areas were weaker than those in the ischemic areas.Meanwhile,the expression of HSP70 and Fos proteins appears firstly in the inner layer of myocardium and extended gradually toward the outer layer.The expression of Fos protein mainly located in the inner layer of myocardium 0 5h after I/R and then extened to the whole layer of myocardium 1h after I/R.The expression of Fos protein in outer layer was stronger than that in inner layer at 4h after I/R.The expression of HSP70 protein located mainly in the inner layer of the myocardium at 1h and 2h after I/R,and then extended to the whole layer of the myocardium at 4h and 6h after I/R.The results indicated that the I/R induced the expression of both HSP70 and Fos proteins in the early stages of myocardial ischemia.The location and the intersity of the immunoreactivity of these two proteins changed at the different stages after I/R.These changes observed in the present study might be useful for the forensic pathological diagnosis of the early myocardial ischemia.