Preventive effect of carvedilol on decrease of tyrosine hydroxylase expression in myocardium of rats with chronic heart failure

AIM: To investigate the effect of carvedilol on the expression of tyrosine hydroxylase(TH) in myocardium of chronic heart failure(CHF) rats.METHODS: Thirty-three adult male Wistar rats were randomly divided into 4 groups: CHF carvedilol administration group(CHF-C group,n=9),CHF metoprolol administration group(CHF-M group,n=9),CHF placebo administration group(CHF-P group,n=9) and normal control group(NC group,n=6).Adrimycin was injected intraperitoneally to the rats of CHF groups to establish CHF models.Carvedilol was administrated intragastrically to rats in CHF-C group at a dose of 0.25 mg/(kg·d) at the 5th week after adrimycin injection.Metoprolol was administrated intragastrically to rats in CHF-M group at a dose of 0.25 mg/(kg·d) at the 5th week after adrimycin injection.Starch was administrated to rats in CHF-P and NC groups.TH mRNA expression in myocardial tissue was analyzed using the reverse transcriptase polymerase chain reaction,and TH protein expression in myocardial tissue was analyzed by Western blot.RESULTS: Compared those in NC group,the expressions of TH mRNA and protein in myocardium significantly decreased in CHF-C group[(0.94±0.31) vs(1.18±0.39),(0.91±0.30) vs(1.32±0.41),P0.05].Compared with those in CHF-P group,the expressions of TH mRNA and protein in myocardium significantly increased in CHF-C group[(0.94±0.31) vs(0.47±0.12),(0.91±0.30) vs(0.41±0.14),P0.01].The expressions of TH mRNA and protein in myocardium were not significantly different between CHF-M group and CHF-P group[(0.66±0.20) vs(0.47±0.12),(0.58±0.19) vs(0.41±0.14),P0.05].CONCLUSION: The expression of TH is significantly decreased in CHF rats' myocardium.Carvedilol can prevent the decrease of TH expression in CHF rats' myocardium.