Effect Of Kangxian Yixin Decoction On SERCA2a Of Myocardial Sarcoplasmic Reticulum Calcium Pump In Rats With Dilated Cardiomyopathy

Objective:To investigate the effect of Kangxian Yixin Decoction on Ca²⁺concentration of sarcoplasmic reticulum and SERCA2a protein and m RNA expression in H9c2 cardiac myocyte hypertrophy model in rat model with dilated cardiomyopathy.Methods:1 Effect of Kangxian Yixin Decoction on Ca²⁺concentration and histopathological morphology of myocardial reticulum in rats with dilated cardiomyopathy:（1）The dilated cardiomyopathy model was prepared by Wistar rats drinking 0.7 g/L of furazolidone aqueous solution on their own;Echocardiography was performed 10 weeks later to determine the success of the rat model.（2）The model rats were randomly divided into the model group,the high-dose group,the low-dose group and the captopril group.Rats in the normal control group were raised routinely without drug intervention.Normal saline of the same volume in the model group and the treatment group;The high-dose and low-dose components of Kangxian Yixin Decoction were 3.6 g/kg·d and 0.9 g/kg·d,respectively.Captopril group was administrated 10.125 mg/kg·d once a day for 8 weeks.（3）Echocardiographic examination was performed to evaluate cardiac function 8 weeks after drug intervention,and cardiac tissue sampling and preservation were performed in rats.Histopathological morphology of cardiac tissue was observed by HE staining.2 Effect of Kangxian Yixin Decoction on SERCA2a protein and m RNA expression levels of the sarcoplasmic reticulum calcium pump in the hypertrophic model of H9c2 myocardium:（1）Norepinephrine induced hypertrophic model of H9c2myocardium,the H9c2 myocardium in logarithmic growth phase was divided into the normal control group,the model group,the high-dose and low-dose groups of Kangxian Yixin Decoction,and the captopril group.（2）For cell is stable after 24 h,8 h hungry,hungry after the end of the normal control group not drug intervention,other groups have a reputation for both to join 100 microns norepinephrine induced H9c2myocyte hypertrophy,fiber good heart side resistance of high dose group to 0.5 mg/ml fiber good heart,fiber good heart side resistance of low dose group join 0.25 mg/ml fiber good heart,captopril group to join 2 x10^-5mol/L captopril intervention,continue to cultivate 24 h.（3）After 24 h,H9c2 myocardial cells were collected and Western Blot and RT-PCR were used to detect the SERCA2a protein and m RNA expression levels of the sarcoplasmic reticulum calcium pump in H9c2 myocardial cells.Results:1 General condition observation of the experimental rats:compared with the normal control group,after 1 month of modeling,the rats in the model group gradually presented a series of symptoms of weakness,mainly including mental inactivity,reduced activity,curling and bunching,rough hair and dark yellow color,and some rats presented physical convulsions,spasms and other symptoms.2 Comparison of the concentration of Ca²⁺in the myocardial sarcoplasmic reticulum of the left ventricle between the two groups:compared with the normal control group,the concentration of Ca²⁺in the myocardial sarcoplasmic reticulum of the model group was significantly decreased（P<0.01）.Compared with the model group,there were significant differences between the high-dose group and the low-dose group and the captopril group（P<0.01）,among which there were also differences between the high-dose group and the low-dose group and the captopril group（P<0.05）,while there was no statistical significance between the low-dose group and the captopril group（P>0.05）.3 Myocardial pathological morphological changes in the left ventricle of rats in each group:the myocardial fibers in the model group were loose in structure and extremely disordered in arrangement,with obvious myocardial fiber rupture,dissolution and heterogeneity of chromatin.In the high-dose group,the myocardial fiber structure was clear and orderly,without fracture or dissolution,and the nuclear size and morphology were basically the same.In the low dose group,the myocardial fiber structure was slightly blurred,the intercellular space was widened,and the nuclei and chromatin were not uniform.4 Comparison of the expression levels of SERCA2a protein and m RNA in the myocardial sarcoplasmic reticulum between each group:compared with the normal group,the expression levels of SERCA2a protein and m RNA in the myocardial sarcoplasmic reticulum in the model group were significantly down-regulated,with statistically significant differences（P<0.01）.Compared with model group,high fiber good heart side resistance,low dose group,captopril group cardiac sarcoplasmic reticulum SERCA2a protein and m RNA expression significantly raised,with statistical difference（P<0.05）,which has fine good heart side high dose group and low dose group,captopril group was also have difference（P<0.05）,resistant fiber good heart low dose group there was no statistically significant difference compared with captopril group（P>0.05）.Conclusion:The Kangxian Yixin Decoction may improve the myocardial systolic function by increasing the Ca²⁺concentration of the sarcoplasmic reticulum in DCM rats and up-regulating the expression levels of SERCA2a protein and m RNA of the cardiac sarcoplasmic reticulum calcium pump.