Objective To observe the effect of electroacupuncture(EA) of "Neiguan"(PC 6) and "Zusanli"(ST 36) on c-fos expression in the nucleus of the solitary tract(NTS)and ischemic electrocardiogram(ECG) in acute myocardial ischemia(AMI) rats

so as to study the role of NTS in EA-induced improvement of AMI.Methods Thirty-six male SD rats were randomly divided into control

model

ST 36

PC 6

"Pianli"(LI 6)

and "Heyang"(BL 55) groups

with 6 cases in each.AMI model was established by intraperitoneal injection of Isoproterenol(5 mg/kg).EA(4 Hz/20 Hz

1 mA) was applied to PC 6

ST 36

LI 6 and BL 55 for 20 min separately.c-fos expression in the NTS was detected by immunohistochemistry and ECG-STⅡ was recorded before and after AMI and EA.Results ① Compared to control group

ECG-STⅡ of model group elevated significantly

while in comparison with model group

ECG-STⅡ values of ST 36 and PC 6 groups decreased significantly(P<0.01)

suggesting an improvement of AMI after EA.No significant changes of ECG-STⅡ were found in LI 6 and BL 55 groups(P>0.05).② The number of fos-immunoreaction(fos-IR) positive neurons in the NTS in ST 36 and PC 6 groups was significantly lower than that in model

LI 6 and BL 55 groups(P<0.01).Conclusion EA of PC 6 and ST 36 can improve ischemic ECG in AMI rats and NTS is one of the centers for integrating cardiac functional activity and information from EA of PC 6 and ST 36.