OBJECTIVE To probe into the relationship between "Xinshu" (BL 15)-"Jueyinshu" (BL 14) of the Bladder Channel and the heart and the underlying mechanism of electroacupuncture (EA) in resisting acute myocardial ischemia (AMI) in rats. METHODS A total of 24 male Wistar rats were randomly divided into control, model and EA groups with 8 cases in each group. AMI model was duplicated by intraperitoneal injection of 2% isoproterenol (ISO, 100 mg/kg). EA (pulse duration 300 micros, frequency 2-20 Hz, output voltage 3. 5-5 V) was applied to BL14 and BL15 on the left side for 30 min, twice in a day (with an interval of 12 h). After decapitation, blood samples, myocardial tissue and spinal cord (T1-T6) were collected respectively for detecting serum creatine kinase (CK, with chromatometry) and calcitonin gene-related peptide (CGRP) contents in the plasma, myocardium and the spinal cord (with radioimmunoassay). RESULTS In comparison with control group, serum CK of both model group and EA group increased significantly (P < 0. 01), and plasma CGRP content of model group lowered lightly; while compared with model group, CK content of EA group decreased obviously (P < 0.05) and plasma CGRP of EA group increased evidently (P < 0.05). No significant differences were found among 3 groups in myocardial CGRP contents and between control group and model group in spinal CGRP contents (P > 0.05). CONCLUSIONS EA of "Xinshu" (BL 15)-"Jueyinshu" (BL 14) may suppress isoproterenol-injection induced myocardial injury and plasma CGRP possibly takes part in the protective effect of EA in resisting myocardial ischemia injury.