Objective To observe the effect of moxibustion on cardiac function and the expression of autophagy-related proteins microtubule-associated protein 1 light chain 3(LC3)and selective autophagy receptor signaling adaptor sequestosome 1(SQSTM1/p62)in rats with chronic heart failure(CHF)

so as to explore its underlying mechanisms in preventing and treating CHF.Methods Sixty male SD rats were randomly divided into normal

model

moxibustion

autophagy inhibitor 3-methyladenine(3-MA)and autophagy agonist rapamycin(RAPA)groups(n=12 rats/group).The CHF model was established by intraperitoneal injection of adriamycin(ADR

2 mg/kg

once every week for 12 weeks).Mild moxibustion was applied to bilateral"Feishu"(BL13)and"Xinshu"(BL15)for 20 min every time.Rats of the 3-MA group were treated by intraperitoneal injection of 3-MA suspension(15 mg/kg)

and those of the RAPA group treated by gavage of RAPA suspension(2 mg/kg).All the treatments were given once a day for 3 weeks.The heart rate(HR)

cardiac output(CO)

left ventricular systolic pressure(LVSP)

left ventricular end-diastolic pressure(LVEDP)and maximum rising and lowering rates of left ventricular pressure(±dp/dtmax)were measured for assessing the cardiac performance.Histopathological changes of the left ventricular myocardium were observed by HE staining.The expression levels of LC3-Ⅰ

LC3-Ⅱ and p62 proteins of the left ventricle myocardium tissue were detected by Western blot.Results After modeling

the pathological changes of myocardium(as myocardial cell swelling with vacuoles

myocardial fibre breakage

etc.)were obvious

and the HR

LVEDP

LC3-Ⅱand LC3-Ⅱ/Ⅰ protein expression levels were significantly increased in the model group compared with the normal group(P<0.01)

while the CO

LVSP

±dp/dtmax

and the expression of p62 protein were significantly down-regulated(P<0.01).Following the interventions

the myocardial injury was reduced

the HR

LVEDP

LC3-Ⅱ and LC3-Ⅱ/Ⅰ levels in both moxibustion and 3-MA groups were significantly decreased(P<0.05

P<0.01)

while the CO

LVSP

±dp/dtmax and p62 expression level were significantly increased relevant to the model group(P<0.05

P<0.01).In addition

the ratio of LC3-Ⅱ/Ⅰ was significantly increased

and the expression level of p62 significantly down-regulated in the RAPA group compared with the model group(P<0.01).Conclusion Moxibustion can improve cardiac function in CHF rats

which may be related to its effects in down-regulating the ratio of LC3-Ⅱ/Ⅰ and up-regulating the expression of p62 protein to inhibit cardiomyocyte autophagy.