| 1Research purposesThe rats with chronic heart failure are treated with Chinese herbal formula Sini Tang(SNT).We will observe the effect of SNT on cardiac function and oxidative stress and explore the mechanism of treating chronic heart failure with SNT.2Research methodsBy using the way of random sampling,after one week of adaptive feeding,80 SD rats were randomly divided into the sham group(n=10)and the model group(n=70).Left coronary artery ligation was used to prepare the rat model of chronic heart failure after myocardial infarction.The rats were randomly divided into 5 groups according to the number of necrotizing Q waves,intraoperative conditions and body weight of the rats that successfully survived heart failure modeling:model group,SNT high dose group?medium dose grou and low dose group,Benner pury group,8 rats in each group.Each group was given the corresponding drug or deionized water for 8 weeks,and the dose was calculated according to the equivalent dose conversion formula between human and rat,among which western medicine group:Benner Pury 0.86mg/(Kg·d)was given by gavage,the traditional Chinese medicine group:the concentrations in the SNT high dose group?medium dose group and low dose group were 11.14g/(Kg·d),5.57 g/(Kg·d)and 2.79g/(Kg·d)respectively.The sham group and the model group were given the same amount of deionized water by gavage,and each group was given gavage once a day.After the drug intervention,echocardiography was performed to measure left ventricular ejection fraction(LVEF),left ventricular short-axis systolic rate(LVFS),left ventricular end-diastolic diameter(LVIDd),left ventricular end-systolic diameter(LVIDs),end-diastolic ventricular septal thickness(IVSd),and end-systolic ventricular septal thickness(IVSs);Biological signals was connected by the right common carotid artery intubation connections,then we collected the processing system,and recorded the heart rate(HR),cardiac index(CI),mean arterial pressure(MAP),left ventricular systolic pressure(LVSP),left ventricular end-diastolic pressure(LVEDP),carotid artery systolic blood pressure(SBP),carotid artery diastolic blood pressure(DBP),left ventricular isovolumetric biggest end systolic pressure rise rate(-dp/dtmax),left ventricular pressure decreases maximum rate(dp/dtmax);Rats were sacrificed to observe the myocardial pathological changes by HE staining and Masson staining.The contents of SOD(superoxide dismutase),GSH-PX(glutathione peroxidase)and H2O2(hydrogen peroxide)in serum were determined by colorimetry,and the contents of MDA(malondialdehyde)were determined by TBA.Western blot was used to detect the expression of SOD and MDA in rat myocardial tissue.3Research results3.1Results of echocardiographyCompared with the sham operation group,LVEF,LVFS,IVSd and IVSs in the model group are significantly decreased,and LVIDs are significantly increased(P<0.01).LVIDd in the model group is on the rise,but there is no significant difference compared with the sham operation group(P>0.05).Compared with the model group,LVEF%and LVFS%are increased and LVIDs is decreased in the Benner pury group and SNT high dose group,medium dose group((P<0.05 or P<0.01).In terms of IVSd and IVSs,there were significant differences between the treatment groups and the model group(P<0.05 or P<0.01),and there was no significant difference between the high,medium and low dose groups of SNT and the western medicine group(P>0.05).3.2Hemodynamic test resultsCompared with the sham group,the model group showed significant differences in SBP,MAP,LVSP,LVEDP,dp/dtmax and CI.LVEDP is significantly increased in the model group(P<0.05),and other indicators were significantly decreased(P<0.05 or P<0.01).All the treatment groups could significantly improve the status of SBP,M AP,LVSP,LVEDP and CI in rats(P<0.05 or P<0.01).Benner pury group and SNT me dium dose group could significantly increase ±dp/dtmax(P<0.05 or P<0.01).3.3Biochemical test resultsCompared with the sham group,the serum SOD and GSH-PX activities of the model group are significantly decreased(P<0.01),and the activity of SOD and GSH-PX in serum of each group is significantly higher than that of the model group(P<0.05 or P<0.01);The contents of MDA and H2O2 in serum of the model group are significantly higher than those in the sham group(P<0.01),and the contents of MDA and H2O2 in each group are significantly lower than those in the model group(P<0.05 or P<0.01).3.4Myocardial histopathological results3.4.1 HE staining results of rats in each groupIn the sham operation group,the myocardial cells are regular and orderly in structure,and the myocardial fibers are intact without degeneration and necrosis.In the model group,the myocardial cells are disordered in size and arrangement,and some myocardial fibers are disordered in shape.The degree of myocardial structure destruction in the other drug intervention groups is significantly improved compared with the model group,and the myocardial fibers are arranged in a more orderly way,among which the myocardial tissue pathological improvement is most obvious in the Benner pury group and SNT medium dose group.3.4.2 Results of Masson staining of rats in each groupArge amount of flaky fibrous tissue,severe myocardial fibrosis and significantly increased CVF are observed in the model group,which is statistically significant compared with the sham group(P<0.01).Compared with the model group,the degree of myocardial fibrosis is significantly reduced in the Benner pury group and SNT high dose group,medium dose group and low dose group(P<0.05 or P<0.01).3.5Oxidative stress related Protein expression resultsCompared with the sham group,the expression of SOD protein in the myocardium of rats in the model group was significantly decreased(P<0.01),while the expression of SOD protein in the western medicine group,the low dose group of SNT inverse decoction and the medium dose group of SNT inverse decoction were all increased(P<0.01).The comparison between the high dose group of SNT inverse decoction and the model group showed no statistical significance(P>0.05),but there was still an upward trend.In terms of MDA,the protein expression level of the model group was significantly higher than that of the sham group(P<0.01),5 and the protein expression level of MDA could be down-regulated in all the treatment groups(P<0.05 or P<0.01).Moreover,there was no significant difference in the expression of SOD and MDA between the western medicine group and the SNT group(P>0.05).4Conclusions(1)SNT can improve the cardiac function of rats with chronic heart failure caused by myocardial in farction and play an antioxidant role.(2)The mechanism of the effect of SNT on the state of oxidative stress in rats with chronic heart failure after myocardial infarction may be related to the improvement of antioxidant capacity and the reduction of oxidative damage. |
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