Objective To observe the effects of electroacupuncture(EA)stimulation of"Neiguan"(PC 6)and"Shenmen"(HT 7)on 5-hydroxytryptamine(5-HT)levels in the paraventricular nucleus(PVN)region of hypothalamus and serum in hyperlipidemia rats with acute myocardial infarction(AMI).Methods A total of 80SD rats with hyperlipidemia were used in the present study.Among them

20rats were randomly selected to be the sham-operation group

and the rest 60cases were used to make the AMI model by occlusion of the anterior descending branch of the left coronary artery.The 60rats who were identified to be successful in AMI were randomly divided into model group

EA-PC 6group and EA-HT 7group(20rats/group).EA(2Hz

2 mA)was applied to bilateral PC 6and HT 7for 20min

once daily for 5days.The contents of 5-HT of hypothalamic PVN region and serum were examined by enzyme linked immunosorbent assay(ELISA)and radioimmunoassay

respectively.Results Following AMI

marked myocardial injury(swelling

breakage

disappearance of local transverse striations and necrosis of myocytes)with infiltration of neutrophil granulocytes was found in the model group

while in both EA-PC 6group and EA-HT 7group

moderate swelling(no breakage)of fewer myocardial fibers with mild infiltration of neutrophil granulocytes was found

indicating a marked improvement of myocardial injury after EA treatment.Compared with the sham-operation group

the content of 5-HT was obviously decreased in the hypothalamic PVN region and significantly increased in serum in the model group(P<0.01).After EA intervention

the content of 5-HT was considerably up-regulated in the hypothalamic PVN region and apparently down-regulated in serum in both EA-PC 6and EA-HT 7groups in comparison with the model group(P<0.01).No significant differences were found between EA-PC 6and EA-HT 7groups in regulating hypothalamic and serum 5-HT levels(P>0.05).Conclusion EA stimulation of both PC 6and HT 7can relieve acute ischemic injury of the myocardium in hyperlipidemia rats

which is probably partially related to its effect in promoting the release of 5-HT from the hypothalamic PVN region.