[Effects of electroacupuncture stimulation of scalp-point on cardiac sympathetic discharges, myocardial beta1-adrenoceptor protein expression and plasma norepinephrine concentration in myocardial ischemia-reperfusion injury rats].

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 beta1-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 beta1-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 beta1-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 beta1-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 beta1-AR protein expression, which may contribute to its effect in relieving myocardial ischemia.