Objective To observe the effect of moxibustion on cardiac function and expression of myocardial tumor suppressor protein p53

mammalian target of rapamycin(mTOR) and phosphorylated(p)-mTOR(excessive autophagy-associated proteins of cardiomyocytes) in rats with chronic heart failure(CHF)

so as to explore its mechanisms underlying improvement of CHF. Methods SD rats were divided into blank control(n=11)

model(n=8)

autophagy activator(n=8)

autophagy inhibitor(n=9) and moxibustion(n=9) groups. The CHF model was established by i.p. injection of Doxorubicin Hydrochloride(DOX

1 mg/mL

1—4 mg/kg) every other day. Moxibustion was applied to bilateral "Feishu"(BL13) and "Xinshu"(BL15) for 20 min

5 times a week for 3 weeks. Rats of the autophagy activator group received gavage of Rapamycin(RAPA

2 mg/kg) and those of the autophagy inhibitor group received i.p. injection of Methyladenine(3-MA

15 mg/kg) 5 times a week for 3 weeks after successful modeling. The heart weight and body weight were measured to calculate heart mass index(HW/BW=heart weight ÷ body weight). Cardiac output(CO) and heart rate(HR) were measured by using a cardiac function meter. Serum N-terminal pro-brain natriuretic peptide(NT-pro BNP) content was assayed by using ELISA

and the expression of myocardial p53

p-mTOR and mTOR proteins was examined by Western blot. Results(1) Compared with the blank control group

the HR

HW/BW

NT-pro BNP content and p53 expression levels were significantly increased(P<0.01)

and the CO and ratio of p-mTOR/mTOR were significantly decreased in the model group(P<0.01).(2) Compared with the model group

the HR

HW/BW and NT-pro BNP content of the autophagy inhibitor and moxibustion groups were significantly decreased(P<0.01

P<0.05)

and CO and p-mTOR/mTOR ratio were significantly increased in both autophagy inhibitor and moxibustion groups(P<0.01).(3) Compared with the autophagy activator group

the levels of HR

HW/BW

NT-pro BNP and p53 in the autophagy inhibitor and moxibustion groups were significantly lower(P<0.01)

and those of CO and p-mTOR/mTOR levels were significantly higher(P<0.01). Conclusion Moxibustion

similar to the autophagy inhibitor

has a protective action on myocardium in CHF rats

which is possible by preventing over expression of myocardial autophagy-associated proteins during CHF.