Effects And Related Mechanism Of Shunxin Decoction Intervention On HFpEF Rats Based On CGMP-PKG Pathway

Objective: To study the effects and mechanism of shunxin decoction on HFpEF rats,which were established by constricting abdominal aortic.Methods: 1.HFpEF rats model: 48 male SD rats were randomly divided into normal group 8,sham group 8,making model group 32.The HFpEF rats were established by constricting the abdominal aorta.Three months after the operation,the rats heart function was detected by ultrasound to evaluate success of the model rats.2.Effects of shunxin decoction on HFpEF rats: 32 HFpEF rats were randomly divided into model group 8,shunxin decoction high dose group 8,shunxin decoction low dose group 8 and qiliqiangxin capsule group 8.Shunxin decoction 3 ml/100g/d,1 ml/100g/d and Qiliqiangxin capsule 1 ml/100g/d respectively were given to rats of shunxin decoction high dose group,shunxin decoction low dose group and qiliqiangxin capsule group by gavage for 14 days.Cardiac function of rats in each group was detected.The serum was collected from the abdominal aorta,and the rats were killed.The hearts,kidneys and brains were separated and weighed,and the heart index was calculated.Part of ventricular tissue was cut from each rat heart for making paraffin sections.Then HE staining and Masson staining were performed to observe the changes in cardiomyocytes morphology and collagen fibers.The ultrastructure of myocardium was observed by electron microscopy.Serum NT-proBNP levels were determined by ELISA.3.Target prediction: The network pharmacology was used to predict the targets of shunxin decoction acting on cGMP-PKG signaling pathway,the targets for detecting were confirmed by relevant references.4.Mechanism research of Shunxin decoction intervention on HFpEF rats: The predicted targets NPRA and GC were detect using immunohistochemical method,eNOS,PDE5 A and PKG I were tested with western blot.Results: 1.The cardiac function of the rats in each group were detected three months after the operation,the IVSd,PWd and E/A of the rats in making model group,were higher than those in the normal group(P<0.05).There were no significant difference in LVEF among the groups.HFpEF rats model were established successfully.2.After drug intervention: Compared with the normal group,IVSd,PWd and E/A values of the model group were higher(P<0.01).Compared with the model group,IVSd,PWd of shunxin decoction high dose group,shunxin decoction low dose group and Qiliqiangxin capsule group were reduced(P<0.01),shunxin decoction high dose group E/A value decreased(P<0.01).Compared with the normal group,the cardiac index of the model group increased(P<0.05).HE staining showed that,compared with the model group,shunxin decoction high dose group,shunxin decoction low dose group and Qiliqiangxin capsule group myocardial cells more neatly arranged.Masson staining showed that,CVF was increased in the model group to compare with the normal group(P<0.05).Electron microscope was used to observe the myocardial ultrastructure,in model group,there were part broken myofibril,part dissolved sarcomere,part muscle wire loosely arranged within myofibril,disintegrated myocardial intercalated disc,some swollen and burst mitochondria.In shunxin decoction high dose group,shunxin decoction low dose group and Qiliqiangxin capsule group,the muscle fibers and mitochondria damage were less than that of model group.Serum NT-proBNP test results,compared with the normal group,the model group NT-proBNP increased(P<0.05).3.Network pharmacology prediction: the confirmed target were NPRA,GC,eNOS,PDE5 A,PKG I.4.Immunohistochemical detection results of NPRA and GC in myocardium: compared with the normal group,the expressions of NPRA and GC in myocardium of the model group were decreased(P<0.01).Compared with the model group,in shunxin decoction low dose group and Qiliqiangxin capsule group myocardium expressions of NPRA,GC increased(P<0.01).WB results of eNOS,PKG I,PDE5A: compared with the normal group,eNOS,PKG I expression of model group decreased(P<0.01),PDE5 A expression increased(P<0.01);Compared with the model group,in shunxin decoction high dose group eNOS expression increased(P<0.01),the PKG I expression increased(P<0.05);PDE5A expression in shunxin decoction high dose group,shunxin decoction low dose group and Qiliqiangxin capsule group myocardial significantly reduced(P<0.01).Conclusion: Shunxin decoction can effectively improve the diastolic function of HFpEF rats.Its mechanism might be that it can increase the NPRA,GC,eNOS expression of myocardial cell cGMP-PKG signaling pathways,upregulate cGMP expression,decrease PDE5 A expression to reduce the cGMP degradation.The two aspects make cGMP continually stimulate PKG I,reversing myocardial hypertrophy,effectively improve HFpEF rats myocardial compliance.