| Objectives:1.To study the activation of p38 MAPK signaling pathway in the process of asphyxiation.3.To investigate the protective effect of edaravone and shenmai injection on myocardium of neonatal rat with asphyxia,and explore the potential mechanism.4.To observe the effect of edaravone、shenmai injection alone or combined in the treatment of neonatal rat with asphyxia.Methods:1.Group and Model establishment:Totally 50 7-day-old Sprague-Dawley(SD)rats were randomly divided into control group(n=10)、asphyxia group(n=10)、Eda group(n=10)、shenmai group(n=10)、Eda + shenmai group(n=10),and put into the 55 ml reagent bottle with ground stopper.Except the control group,all the bottlenecks were smeared with vaseline.Cover the bottle stopper,take out the rats after 30 min.2.Treatment:3 min after the model was successfully established,the rats were treated with shenmai injection(2ml)、edaravone(2mg)、and normal saline(4ml)divided into two parts by intraperitoneal injection.Speciments were collected after reoxygenation 120 min.3.Observation:the expression of myocardial enzyme,the pathological changes,p-p38 MAPK and Bcl-2 protein levels in cardiac muscle tissue,and myocardial apoptosis with Tunel analysis.Results:1.The expression of myocardial enzyme: The CK and LDH levels in all groups except those in the normal control group were significant rise(P<0.01).Compared to asphyxia group,CK and LDH levels were reduced in shenmai group、Eda group and Eda + shenmai group(P<0.05),the CK levels among the Eda group and Eda +shenmai group reduced more than the shenmai group(P<0.05).However,the CK levels shown no significant differences between Eda group and Eda + shenmai group(P>0.05),and the LDH levels shown no significant differences between shenmai group、Eda group and Eda + shenmai group(P>0.05).2.The HE staining of Myocadial tissue:Myocardial cells were arranged rules and neat,the cytoplasm of uniform light dye,clear nedei,tissun interstitial edema,rare inflammatory cell infiltration in normal control group.Myocardial cells were disordered arrangement,a portion of the muscle fiber fracture,irregular nucleus,a concentrated form,some cells necrosis,endear disappear,sample cells in vacuoles,interstitial hyperemia and edema,obviously a lot of inflammatory cells infiltration in the asphyxia group.Compared to the asphyxia group,above changes were significantly reduce between Eda group、shenmai group and Eda + shenmai group.The arrangement of myocardial cells were mild disorder,myocardial interstitial hyperemia edema and cell necrosis is not obvious,and it can be foud only a small amout of inflammatory cells infiltration.3.p-p38 MAPK and Bcl-2 protein levels in cardiac muscle tissue:The p-p38MAPK、Bcl-2 protein levels in all groups except those in the normal control group were significant rise(P<0.01).Compared to the asphyxia group,p-p38 MAPK protein levels were reduced and Bcl-2 protein levels were enhanced in shenmai group、Eda group and Eda + shenmai group(P<0.05～0.01).The p-p38 MAPK protein levels among the Eda group and Eda + shenmai group reduced more than the shenmai group(P<0.05).However,the p-p38 MAPK protein levels shown no significant differences between Eda group and Eda + shenmai group(P>0.05),and the Bcl-2protein levels shown no significant differences between shenmai group、Eda group and Eda + shenmai group(P>0.05).4.Results of fluorescent chromogenic myocardial cell apoptosis index(AI):The normal control group only a small number of apoptosis cells fluorescent color,but the rest of the groups of apoptosis cells were more,AI level increased significantly(P<0.01).Compares with asphyxia group,the number of apoptosis cells fluorescent color were decreased in shenmai group、Eda group and Eda + shenmai group,and the levels of AI were droped(P<0.01),the AI levels among the Eda group and Eda + shenmai group were droped more obvious than shenmai group(P<0.05).However,the AI levels shown no significant differences between Eda group and Eda + shenmai group(P>0.05)Conclusions:1.p38 MAPK signaling pathway was activated in the process of myocardial damage induced by asphyxia,the activation of p38 MAPK enhance the p-p38 MAPK protein levels and myocardial cell apoptosis.2.Edaravone 、shenmai injection reduce the myocardial cell apoptosis of neonatal rat with asphyxia through down-regulating p38 MAPK activation and upregulating Bcl-2 protein levels.3.The combination of edaravone plus shenmai injection is more effective than shenmai injection,but not more effective than Edaravone... |
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