Abstract:

Abstract:Objective To study the effect of astragaloside Ⅳ (AsⅣ) on myocardial ischemia-reperfuion injury in rats and clarify its mechanism.Methods The models of myocardial ischemia-reperfusion injury in rats were established.30 male Wistar rats were divided into sham-operation group,ischemia-reperfusion model group,positive drug NIC group，AsⅣ group(5 mg/kg,10 min before ischemia),AsⅣ+chelerythrine chloride(CHE) group （3 mg/kg）.The activities of serum LDH and SOD and contents of serum MDA and NO in rats were measured.The morphological changes of cardiocytes in rats were observed by light microscopy.The protein expression of PKCε was analyzed by Western blotting.Results The LDH activity and MDA content in AsⅣ group were lower than those in model  group (P＜0.05 or P＜0.01),and the SOD activity and NO content were higher in AsⅣ group than those in model group (P＜0.01).HE staining results confirmed that AsⅣ could obviously ameliorate cell structure and reduce inflammatory cell infiltration.AsⅣ could increase the protein expression of PKCε in membrane.CHE abolished the protective effect of AsⅣ partly, compared with AsⅣ group,the LDH activity and MDA content were increased(P＜0.05),the SOD activity was decreased(P＜0.05),the protein expression of PKCε in membrane was decreased(P＜0.05),the cardiocytes had serious edema and the cytoplasm was stained slightly in AsⅣ+CHE group.Conclusion AsⅣ possesses an obviously protective effect on myocardial ischemia-reperfusion injury in rats by increasing NO content. PKCε may be the down stream of NO which is involved in the transduction of AsⅣ.

Key words: astragaloside　Ⅳ;myocardial ischemia;myocardial reperfusion injury;nitric oxide;protein kinase C-epsilone