Objective To observe the effect of electroacupuncture(EA)intervention on expression and content of protein kinase C(PKC)in the middle cerebral artery in acute cerebral infarction(ACI)rats so as to explore its mechanism underlying improvement of ACI.Methods Wistar rats were randomly divided into normal control(n=6)

sham operation(n=30)

ACI model(n=30)

and EA(n=30)groups

and the latter three groups were further divided into 0.5h

1h

3h

6hand 12hsubgroups(n=6in each subgroup).The ACI model was established by occlusion of the middle cerebral artery(MCAO).EA(15Hz

1mA)was applied to"Shuigou"(GV 26)for 20 min.The PKC expression levels and activity in the vascular smooth muscle of the middle cerebral artery were detected using immunohistochemistry and ELISA

respectively.Results In comparison with the control group

the immunoactivity and activities of PKC in the middle cerebral artery tissue at 0.5h

1h

3h

6hand 12 hwere significantly increased in the model group(P<0.05).After EA intervention

the expression levels and activities of PKC at the 5time-points were markedly down-regulated in comparison with the model group at the same corresponding time-point(P<0.05).No significant changes of PKC expression and activity were found in the sham operation group(P>0.05).Conclusion EA intervention can up-regulate the immunoactivity and activity of PKC in the vascular smooth muscle of the middle cerebral artery in ACI rats

which may contribute to its effect in improving ACI by relieving arterial spasm.