Objective To observe the effect of electroacupuncture(EA) preconditioning on expression of Caspase-1

Gasdermin D(GSDMD) and interleukin-1β(IL-1β) in myocardial tissue of myocardial ischemia reperfusion injury(MIRI) rats in order to explore its underlying mechanisms in resisting MIRI. Methods Forty male rats were randomly divided into 4 groups: normal control(normal)

sham operation(sham)

MIRI model and EA groups. The MIRI model was established by ligation of the left anterior descending branch of the left coronary artery for 30 min and perfusion. EA(2 Hz/100 Hz

1 mA) was applied to bilateral “Neiguan”(PC6) for 20 min

once a day for 3 consecutive days. The echocardiography was used to analyze the left ventricular end-diastolic dimension(LVEDD)

left ventricular end-systolic dimension(LVESD) and left ventricular ejection fraction(LVEF

by using Teichholz formula) 4 h after modeling. The myocardial TTC staining was used to observe the proportion of the infarct area

and Western blot was used to detect the expression levels of GSDMD

Caspase-1

IL-1β proteins in the myocardium. Results Compared with the normal group

the immunoactivity of GSDMD was increased in the sham group(P<0.05). Compared with the sham group

the LVEF was significantly decreased(P<0.000 1)

while the myocardial infarction area

immunoactivity of GSDMD

and the expression levels of Caspase-1

GSDMD and IL-1β proteins were considerably increased in the model group(P<0.000 1

P<0.001). In comparison with the model group

the decreased ejection fraction and the increased myocardial infarction area

and Caspase-1

GSDMD and IL-1β expression were reversed in the EA group(P<0.001

P<0.000 1

P<0.01). Conclusion EA preconditioning may ameliorate myocardial injury in MIRI rats which may be associated with its function in down-regulating the expression of myocardial Caspase-1 protein to reduce cardiomyocyte pyroptosis.