Objective: To investigate the protective mechanisms of electroacupuncture (EA) on cerebral ischemic injury. Methods: SD rats were randomly and evenly divided into control group

sham operation group

ischemia(I) 2 hr group

I reperfusion (R) 2 hr group

I R 6 hr group

I R 12 hr group

I R 24 hr group

I R 2 hr+EA group

I R 6 hr+EA group

I R 12 hr+EA group and I R 24 hr+EA group (with 5 rats in each group). "Baihui"(GV 20) and "Shuigou"(GV 26) of the 4 ischemia+EA groups were stimulated with EA (20/4 Hz

3 mA and duration of 1 hr). RT PCR was used to explore the effects of electroacupuncture (EA) on interleukin 1 receptor antagonist (IL 1Ra) mRNA expression in rats with middle cerebral artery occlusion (MCAo). Results: IL 1Ra mRNA expression was rapidly induced by MCAo

and increased significantly at 12 hr (0.770±0.076)

reaching a peak level at 24 hr after reperfusion in the ischemic cortex area(0.994±0.098) compared with normal group (0.475±0.069

P<0.001). IL 1Ra mRNA also increased significantly after 12 hr IR in striatum (0.796±0.103) compared with normal group (0.521±0.061

P<0.05). However

IL 1Ra mRNA decreased after 24 hr IR in ischemic striatum (0.500±0.118). The expression of IL 1Ra mRNA in EA group increased significantly compared with ischemia control group after reperfusion 12 hr (0.890±0.087 vs 0.770±0.076 ) and 24 hr in cerebral cortex (1.201±0.155 vs 0.994±0.098 ) and 24 hr in stratium (1.046±0.132 vs 0.500±0.118)

P<0.05

P<0.001. Conclusion: The results indicated that EA could upregulate the IL 1Ra mRNA expression in ischemia rats

that may contribute to the protective action of EA in reducing ischemic brain injury.