Objective: To explore the protective effect of electroacupuncture(EA) on the activity of cerebral cytochrome C oxidase and mitochondrial DNA(MtDNA) in cerebral ischemia-reperfusion(CI/R) rats.Methods: Forty-eight male SD rats were evenly randomized into shamoperation

sham-operation+EA

model

and model+EA groups with 12 cases in each group.CI/R model was established by middle cerebral artery occlusion(MCAO) under anesthesia(7% chloral hydrate

(1 mL)/(200 g)).EA(1-(4 mA)

(5/20 Hz)

dense-sparse waves) was applied to "Shuigou"(GV 26) and "Baihui"(GV 20) for(30 min) first

suspended for 15 min and then 30 min again.The rats in each group were sacrificed for taking out the right hemisphere of the brain and the cerebral mitochondria were isolated by differential centrifugation.Mitochondria suspension((1 mg/mL) protein) were frozen and thawed three times under temperature of(-20 ℃).The activity of complex IV(cytochrome C oxidase) was estimated by spectrophotometry and figured out according to formula: enzyme activity [μmol/(min·mg mitochondria protein)]= K·cytochrome C concentration/ protein concentration [K is the ratio between nature Logarithm of OD values and time(min) of six time points at the wavelength of 550 nm)].MtDNA was isolated and purified according to DNA isolation kit.The concentration of MtDNA was determined by spectrophotometry.DNA damage levels were measured by agarose gel electrophoresis.Results: Compared with sham-operation and sham-operation+EA groups

the activity of cytochrome C oxidase was significantly lower in model group((P<0.01))

while compared with model group

the activity of this enzyme in model+EA group was obviously higher(P<0.01)

indicating an increase of the activity of cytochrome C oxidase after EA.There was no significant difference between sham and sham+EA in the activity of this oxidase.MtDNA in the core of the brain focus and penumbra region were both damaged seriously.DNA ladder was found in the core.DNA damage extent in the penumbra region reduced after EA treatment

but not in the core region.Conclusion: EA can reduce the injury of mitochondrial function

which may result from its effect in alleviating the oxidative stress of the brain cells in MCAO rats.