Objective To explore the mechanism of electroacupuncture(EA) of scalp-point in the management of myocardial ischemia-reperfusion injury(MI/RI) by examining its effects on left cardiac sympathetic nerve activity

myocardial β1-adrenaline receptor(AR) protein expression and plasma norepinephrine(NE) concentration in MI/RI rats.Methods Eighteen Wistar rats were randomly divided into sham

model and EA groups(n=6).MI/RI model was induced by ligation of the left anterior descending coronary artery for 30 min

followed by release of the ligation for 15 min.EA was applied to bilateral Epangxian I(MS 2) for 15 min.The left cardiac sympathetic nerve activity was recorded with BL-420 E+ biological signal acquisition system.Myocardial β1-AR protein expression was examined by western blot and plasma NE level detected by enzyme-labeled immunosorbent assay.Results Compared with the sham group

the left cardiac sympathetic discharges and plasma NE levels and myocardial β1-AR protein expression were markedly increased in the model group(P<0.01)

whereas in comparison with the model group

the sympathetic discharges

plasma NE level and myocardial β1-AR protein expression in the EA group were down-regulated significantly(P<0.05).Conclusion Scalp-point EA intervention can suppress MI/RI induced increase of sympathetic nerve activity and plasma NE level

and β1-AR protein expression

which may contribute to its effect in relieving myocardial ischemia.