Zhenwu Decoction Delays Ventricular Hypertrophy In Rats With Uremic Cardiomyopathy,A Preliminary Study

Background:Cardiac remodeling is the pathological feature of cardiac lesions in uremic patients.The histopathological changes include myocardial hypertrophy and myocardial interstitial fibrosis.Indoxyl-sulfate(IS),as a non-covalently binding protein,plays a toxic role in cardiac remodeling in uremia cardiomyopathy.Zhenwu Decoction has a good effect in the research and treatment of heart and kidney diseases.In our previous clinical studies found that Zhenwu Decoction can reduce plasma IS levels and improve heart and kidney function in Uremia patients.Therefore,this study will explore the effect of zhenwu decoction on the changes of plasma IS level,ventricular hypertrophy and cardiac fibrosis in rats with uremia cardiomyopathy,and explore its mechanism.Objective:This research aimed at exploring the effect of Zhenwu Decoction on ventricular hypertrophy and fibrosis in uremic cardiomyopathy rats,and explore its mechanism of action through cell experiments.Methods:Thirty SD rats were randomly divided into sham operation group,model group,Zhenwu Decoction low-dose group(4.5 g/kg),Zhenwu Decoction high-dose group(13.5 g/kg).except for those in the sham operation group,all the rats underwent 5/6 nephrectomy.Four weeks after the operation,the rats in low-and high-dose treatment groups were given Zhenwu Decoction via gavage at the dose of 4.5 g/kg and 13.5 g/kg,respectively;the rats in the sham-operated and model groups were given an equal volume of distilled water.After 4 weeks of treatment,,serum levels of IS were determined,and cardiac and ventricular mass indexes were measured in the rats;heart was stained in different ways:HE staining,Masson staining.cardiac ultrasound was performed and Western blotting was used to measure the expressions of ANP,BNP,COLI,TGFβ,aSMA,p-ERK1/2,p-p38 and p-JNK in the myocardial tissue.The expression levels of ANP、BNP、βMHC、COLI、TGFβ、CTGF mRNA were detected by real-time quantitative PCR(qPCR).SD rat cardiomyocytes and fibroblasts were extracted,and cardiomyocytes and fibroblasts were divided into control group,control+IS(10um)group,drug-containing serum+IS(10um)group.The protein synthesis rate of cardiomyocytes was detected by[3H]leucine incorporation method,the protein synthesis rate of fibroblasts was detected by[3H]proline incorporation method.And the proteins of different groups were detected by Western blot.Results:1.In vivo experiments showed that the renal function of the model group decreased,plasma IS level was significantly higher than that of the sham group(P<0.01),and the results of LVMI,cardiac ultrasonography index,myocardial tissue protein ANP,BNP,COL,aSMA,myocardial tissue ANP,BNP,βMHC,TGFβ,COLI,CTGF mRNA,HE and Masson staining showed that the rat of model group had obvious hypertrophy and fibrosis in the ventricle.2.As a result of in vitro experiments,IS significantly induced up-regulation of cardiomyocyte and fibroblast-associated protein expression,and accelerated the rate of protein synthesis(P<0.01).3.The IS level in the low dose group and the high dose group decreased,and the improvement effect in the high dose group was better than that in the low dose group(P<0.01).the results of LVMI,cardiac ultrasonography index,myocardial tissue protein ANP,BNP,COL,aSMA,myocardial tissue ANP,BNP,βMHC,TGFβ,COLI,CTGF mRNA,HE and Masson staining showed that the improvement of ventricular hypertrophy and fibrosis in the high-dose group was more obvious.4.In vitro experiments showed that the expression of protein and protein synthesis rate of cardiomyocytes and fibroblasts in drug-containing serum+IS group were significantly lower than those in control+IS group(P<0.01).5.The expressions of p-ERK,p-P38 and p-JNK protein in myocardial tissue of rats in high dose group were lower than those in model group.In vitro,the expression of p-ERK and p-P38 was up-regulated in control+IS group of cardiomyocytes and fibroblasts,while the expression of p-ERK and p-P38 in the drug-containing serum+IS group was significantly down-regulated.And p-JNK protein expression in the cell groups was no significant difference.Conclusion:On the one hand,Zhenwu Decoction can reduce plasma IS level and reduce the effect of IS on cardiotoxicity;on the other hand,the efficacy component of Zhenwu Decoction may improve IS-induced cardiomyocyte hypertrophy and fibroblast fibrosis by inhibiting ERK and P38 signaling pathways.