| Objective To observe the myocardial protective effects of Guanxinning tablet(GXNT)on myocardial ischemic reperfusion injury(MI/RI)in rats,and further to explore its role mechanism.Methods Seventy SD rats were divided into 7 groups randomly(n=10);the sham group,the MI/RI group,75 mg/kg,150 mg/kg,300 mg/kg and 600 mg/kg GXNT groups and 300 mg/kg Compound Danshen Tablets(DST)group.All rats were administered orally for 7 days,and then the MI/RI model was made by ligating the left anterior descending branch of coronary artery in rats.The changes of electrocardiogram were recorded and the electrocardiogram of J points and heart rate variability(HRV)parameters were analyzed.At the end of reperfusion,the myocardial infarct size was measured by using Evans blue and tetrazolium chloride(TTC)double staining.The changes of the activities of serum aspartate aminotransferase(AST),lactate dehydrogenase(LDH),creatine kinase(CK)and its isozyme(CK-MB),superoxide dismutase(SOD),malondialdehyde(MDA)content and nitric oxide(NO)level were also detected.Meanwhile,the pathological change of myocardial was observed by HE staining.Moreover,the changes of the activities of SOD,MDA,NO,myeloperoxidase(MPO)and total antioxidant capacity(T-AOC)in myocardial tissues were also detected.Results Compared with sham group,,the J point of ECG in.the MI/RI rat was significantly elevated during ischemia period(P<0.01),while the J point during reperfusion was lowed,but still higher than that of sham group(P<0.01).RR interval,SDNN,RMSSD,TP and HFnu in MI/RI rats were significantly reduced,while LFnu and LF/HF were significantly increased(P<0.01),the extent of myocardial ischemia(ARR/WH and ARR/LV)and myocardial infarction size(INF/WH,INF/LV and INF/ARR)were significantly increased(P<0.01),the activities of serum AST,LDH,CK and CK-MB were significantly increased(P<0.01),and the activities of SOD,T-AOC and NO in serum or myocardial tissues were significantly reduced(P<0.05,P<0.01),while MDA content and MPO activity were significantly increased(P<0.05,P<0.01).Moreover,the myocardial fiber swelling and disorder with a wave like change and some myocardial fibers were broken,the nucleus has broken and dissolved as well as disappeared.There was inflammatory cell infiltration in the myocardial interstitial,focal necrosis and hemorrhage were observed in MI/RI rats.All of which suggest that MI/RI rats have obvious myocardial injury,the productive of free radicals was increased,obvious oxidative stress and inflammation reaction,and finally the cardiac autonomic nervous function was disordered.Treatment with GXNT and DST can significantly reduce J point,total J point and the average of J point during reperfusion(P<0.05,P<0ยท01),significantly reduce the extents of myocardial ischemia and infarction size(P<0.05,P<0.01),significantly increase SDNN,RMSSD,TP and HFnu and reduce LFnu and LF/HF,and inhibit the serum AST,LDH,CK and CK-MB release(P<0.05,P<0.01),increase the serum SOD activity and NO level(P<0.05,P<0.01),and reduce the MDA content(P<0.05,P<0.01).Meanwhile,which can significantly increase the activities of SOD,T-AOC and NO as well as low the MDA content and MPO activity in myocardial tissues(P<0.05,P<0:01),and improve the myocardial pathological structure.Conclusion Guanxinning tablet has anti-MI/RI effects by anti-oxidation and inhibition inflammatory reaction,and improve the regulation of autonomic nervous function,and further to relieve myocardial infarction in MI/RI rats. |
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