OBJECTIVETo observe anti-arrhythmic effect of acupuncture pretreatment in the rat of myocardial ischemia and reperfusion (MIR) and to explore the role of cAMP and Gsa protein in beta-adrenergic receptor signaling.

METHODSMIR was produced by ligation and reperfusion of the left anterior descending coronary artery in the rat. Arrhythmic score, content of cAMP and Gsalpha protein in ischemic myocardium were compared among the normal control (NC), ischemia and reperfusion (IR), electroacupuncture (EA) and EA plus propranolol (EAP) groups.

RESULTSThe arrhythmic score in the IR group at 10 min after reperfusion was higher than the NC group (P < 0.01); in the EA group the score was decreased (P < 0.01 vs the IR group); the score in the EAP group was similar to the IR group, much higher than the EA group (P < 0.01). The similar results for the contents of cAMP and Gsalpha protein were found in the ischemic myocardium. It is suggested that EA pretreatment significantly attenuates the arrhythmic incidence rate and the enhancement of the contents of myocardial cAMP and Gsalpha protein induced by MIR, and the attenuating effect is significantly inhibited by the intraperitoneal pretreatment of propranolol, a specific beta-adrenoceptor antagonist.

CONCLUSIONPretreatment of EA can produce anti-arrhythmic effect in the rat of MIR, which is mediated by the post-receptor signaling pathway of beta-adrenergic receptor.