Objective To explore the effect of electroacupuncture(EA) in resisting acute cerebral ischemia-reperfusion injury(CI-RI) via anti-oxidation of melatonin(MT).Methods A total of 52 male SD rats were randomized into Sham-operation(sham

n=8)

CI-RI(model

n=8)

EA(n=8)

MT(3.2 mg/Kg

i.p.

n=8)

EA+MT(n=8)

EA+Luzindole(L

a blocker of MT

1 mg/100 μl/rat

n=6)

EA+PD 98059(a blocker of mitogen-activated protein kinase

MAPK

1 mg 100 μl/rat

n=6) groups.EA(3 Hz

1-3 mA

continuous waves) was applied to "Dazhui"(GV 14) and "Baihui"(GV 20) for 30 min.CI-RI model was induced by right middle cerebral artery occlusion(MCAO) for 60 min and reperfusion for 24 h except sham-operation group.MT content of pineal gland tissue was determined by high performance liquid chromatography(HPLC) and neuroethological scores of the rats were evaluated by Kuluz's and Julio's methods.Bax and Bcl-2 gene protein expression of the striate body was detected by immunohistochemistry.Results In comparison with sham group

the number of Bax immunoreactive(IR) positive cells and Bax/Bcl-2 in striate body increased significantly(P<0.001)

and neuroethological score and Bcl-2 IR-positive cells decreased considerably in model group(P<0.01).Compared with model group

pineal MT content

neuroethological score and Bcl-2 IR-positive cells in EA group

neuroethological scores in EA+L and EA+P groups

and Bcl-2 expression in MT and EA+MT groups increased considerably(P<0.01

0.001);while Bax IR-positive cells and Bax/Bcl-2 in EA

MT and EA+MT groups decreased very significantly(P<0.001).It showed that EA could obviously increase pineal MT content

improve CI-RI rats' activity score

upregulate Bcl-2 expression and down-regulate Bax expression in striate body.In comparison with simple EA group

neuroethological scores of EA+L and EA+P groups

Bax IR-positive cells and Bax/Bcl-2 of EA+MT group were significant lower(P<0.05

0.01).No significant differences were found between EA+L and EA+P groups in behavior scores

and between MT and EA+MT groups in Bax and Bcl-2 IR-positive cell number and Bax/Bcl-2(P>0.05).Conclusion EA has a good effect of anti-oxygen stress

protecting the brain from ischemic damage directly or indirectly

which may be related to its effect in upregulating the synthesis and release of MT.