Effects of Optimized New Shengmai Powder in Modulating β1-AR/cAMP/PKA/CREB Signaling Pathway on Myocardial Fibrosis in Rats with Heart Failure / 中国中医药信息杂志

ABSTRACT

Objective To investigate the effects of Optimized New Shengmai Powder on myocardial fibrosis in rats with heart failure based on the β1-AR/cAMP/PKA/CREB signaling pathway.Methods Totally 50 SD rats were randomly divided into sham-operation group(10 rats)and operation group(40 rats).The left anterior descending coronary artery was ligated to establish a rat model of heart failure.The modeling rats were randomly divided into the model group,the captopril group,and TCM low-and high-dosage groups,with 8 rats in each group.The administration groups received relevant medicine for gavage for 4 weeks.LVEF and LVFS in rats were detected by echocardiography,and measurement of heart and lung mass and calculation of heart and lung organ coefficients were performed,myocardial fibrosis degree was observed by histopathology,serum NT-ProBNP and cAMP,Col Ⅰ,and Col Ⅲcontent in myocardial tissue were detected by ELISA,immunohistochemical was used to detect β1-AR,cAMP positive expression,and Western blot was used to detect the expression of β1-AR/cAMP/PKA/CREB signaling pathway related proteins.Results Compared with the sham-operation group,the LVEF and LVFS of the model group rats were significantly decreased(P<0.01),and the heart and lung organ coefficient significantly increased(P<0.01);the number of myocardial cells decreased,collagen volume fraction increased,and the proportion of type Ⅰ/Ⅲcollagen fibers increased(P<0.01),the contents of serum NT-ProBNP and myocardial tissue Col Ⅰ and Col Ⅲincreased significantly,while the cAMP content in myocardial tissue decreased significantly(P<0.01),the positive expressions of β1-AR and cAMP were significantly decreased(P<0.01),the expressions of β1-AR,AC1,cAMP,p-PKA,and p-CREB proteins were significantly decreased,while protein expressions of p-Smad2,Col Ⅰ,Col Ⅲ,and α-SMA significantly increased(P<0.05,P<0.01).Compared with the model group,the administration groups could increase LVEF and LVFS and decrease heart and lung organ coefficient to different degrees in rats;increase the number of myocardial cells,decrease collagen volume fraction and the proportion of type Ⅰ/Ⅲ collagen fibers,down-regulate serum NT-ProBNP and the content of Col Ⅰ and Col Ⅲ in myocardial tissue,up-regulate the content of cAMP,increase the positive expressions of β1-AR and cAMP in myocardial tissue,up-regulate β1-AR,AC1,cAMP,p-PKA,p-CREB protein expression,and inhibit p-Smad2,Col Ⅰ,Col Ⅲ,and α-SMA protein expression,in which the effects of the TCM high-dosage group and captopril group were more pronounced(P<0.01,P<0.05).Conclusion Optimized New Shengmai Powder can effectively reduce myocardial fibrosis in heart failure rats,improve myocardial hypertrophy and remodeling,and increase left ventricular contractility,and the mechanism may be related to the activation of the β1-AR/cAMP/PKA/CREB signaling pathway.