肌肉质量对腹主动脉缩窄大鼠心脏结构和功能的影响OA北大核心CSTPCD

AIM:To investigate the effects of skeletal muscle mass on cardiac structure and function in rats subjected to abdominal aortic constriction(AAC),and to explore its potential mechanisms.METHODS:(1)Thirty male SD rats were randomly divided into 3 groups:control(CON)group(n=10),muscular atrophy(MA)group(n=10),and muscular hypertrophy(MH)group(n=10).The rats in MA group underwent bilateral tibial nerve removal to induce MA,while those in MH group engaged in weight-bearing running to promote MH.Four weeks later,skeletal muscle sam-ples were collected,and indicators of MA and MH were assessed.(2)Another rats after modeling above were divided into 4 groups:CON group(n=10),cardiac pathological remodeling group(AAC group;n=10),MA+AAC group(n=10),and MH+AAC group(n=10).All rats,except those in CON group which underwent a sham operation,received AAC sur-gery.Four weeks after surgery,cardiac structure and function were assessed by echocardiography,while morphological changes of the soleus and gastrocnemius muscles and myocardium were evaluated by pathological staining.Serum myo-statin(MSTN)level was measured using ELISA.The mRNA expression levels of atrial natriuretic peptide(ANP)and brain natriuretic peptide(BNP)in the myocardium,and MSTN in the skeletal muscle and myocardium were detected by real-time PCR.RESULTS:After 4 weeks of either denervation or weight-bearing running,significant atrophy and hyper-trophy of the gastrocnemius and soleus muscles were observed in MA and MH groups,respectively,compared with CON group.However,no significant differences were noted in heart weight/body weight ratio,left ventricular end-diastolic wall thickness,ejection fraction,or other related indexes among these groups(P>0.05).In comparison to AAC group,the rats in MA+AAC group showed a significant increase in heart weight/body weight ratio and left ventricular end-diastolic an-terior wall thickness,a decrease in end-diastolic internal diameter,an increase in ejection fraction(P<0.05 or P<0.01),and exacerbated myocardial fibrosis.Conversely,in MH+AAC group,there was a significant decrease in heart weight/body weight ratio and left ventricular end-diastolic wall thickness,an increase in end-diastolic internal diameter,and a lower ejection fraction(P<0.05 or P<0.01),with reduced myocardial fibrosis.Compared with AAC group,myocardial ANP and BNP mRNA expression significantly increased in MA+AAC group and decreased in MH+AAC group(P<0.01).Additionally,soleus and gastrocnemius muscle MSTN mRNA expression,myocardial MSTN mRNA expression,and se-rum MSTN level significantly increased in MA+AAC group(P<0.01)and significantly decreased in MH+AAC group(P<0.05).CONCLUSION:Atrophic skeletal muscle exacerbated the pathological remodeling induced by AAC surgery,whereas hypertrophic skeletal muscle mitigated this remodeling.Skeletal muscle mass plays a critical role in cardiac patho-logical remodeling,with MSTN potentially regulating this process.