Abstract: Objective: To investigate the regulatory effects of curcumin on Renin-angiotensinⅡ(AngⅡ)-aldosterone (ALD) system(RAAS) in the rats with chronic heart failure, and to elucidate its therapeutic mechanism.Methods: Fifty male SD rats were selected and randomly divided into sham operation group, model group, low dose of curcumin group,middle dose of crucumin group and high dose curcumin of group(n=10). In sham operation group, the left ventricles of the rats were opened only to expose the left anterior descending coronary artery without ligation and conventional feeding. The abdomen of the rats in other groups were opened in the xiphoid abdomen and the left anterior descending coronary arteries were ligated to establish the rat models with chronic heart failure.The rats in low,middle,and high doses of curcumin groups were intragastrically adminstrated with 20,40,and 80 mg·kg^-1 curcumin,and the rats in sham operation group and model group were administrated with normal saline at the same volume; continuous administration for 30 d. The heart function of the rats was measured by echocardiography. The blood was taken from the abdominal aorta.ELISA was used to detect the levels of serum Renin, AngⅡ and ALD of the rats in various groups.The expression levels of angiotensin type 1 receptor(AT1R) and agniotensin-converting enzyme(ACE) mRNA in myocardium tissue of the rats in various groups were detected by RT-PCR method.Western blotting method was used to detect the expression levels of ACE and AT1R proteins in myocardium tissue of the rats in various groups.Results: Compared with model group, the left ventricular end systolic diameter (LVESD) and left ventricular end diastolic diameter(LVEDD)in low, middle, and high doses of curcumin groups were significantly decreased(P<0.05), while the left ventricular ejection fraction (LVEF) were significantly increased(P<0.05). Compared with model group, the levels of Renin, AngⅡ and ALD in the serum of the rats in low, middle, and high doses of curcumin groups were significantly decreased (P<0.05).Compared with model group, the expression levels of ACE and AT1R mRNA in the myocardium tissue of the rats in low, middle, and high doses of curcumin groups were significantly decreased (P<0.05);compared with model group, the expression levels of ACE and AT1R proteins in the myocardium tissue of the rats in low, middle, and high doses of curcumin groups were significantly decreased (P<0.05).Conclusion: Curcumin has a dose-dependent inhibition for the RAAS in the chronic heart failue rats and can improve the cardiac function of the chronic heart failure rats.

Key words: curcumin, chronic heart failure, renin, angiotensinⅡ, aldosterone