Objective To observe the effect of electric acupuncture on the infarct volume and amount of cerebral cortex and spinal neuron at different times of cerebral ischemia/reperfusion(I/R)in stroke prone renovascular hypertensive rats(RHRSP)with middle cerebral artery occlusion(MCAO),and investigate the possible mechanisms of electric acupuncture on remote damage in ischemic stroke. Methods 480 male SPF Sprague-Dawley(SD)rats were duplicated to form the RHRSP models by clamping both kidneys. 370 successful ones were selected by taking the tail artery blood pressure,and divided into hypertension group and sham operation group(each n=60)by random number table method. The MCAO models were created by stringing middle cerebral artery in the remaining RHRSP. The nerve function defect score(NDS)was graded by Longa 5 point method after the rats waked up from anesthesia,then the ones scored 1-3 were enrolled. Totally,there were 190 rats with MCAO successfully created from which 10 were randomly selected to determine the infarct size by 2,3,5-triphenyl four azole nitrogen chloride(TTC)staining. The remaining 180 MCAO rats were randomly divided into model group,electric acupuncture group and fake acupuncture group(each n=60). The sham operated group only received surgical trauma;the electrical acupunctures atBaihuiandDazhuiacupoints on Du channel were performed on the day of model establishment in electric acupuncture group,once a day for 28 days;in fake acupuncture group,sticked the acupuncture needles at the skin ofBaihuiandDazhuipoints,then gived the same electrical acupuncture treatment. On 1,7,14 and 28 days after treatment,the rats of each group were respectively sacrificed,and the brains were collected,then the infarct volume and spinal neuron number were calculated by Nissl staining. Results ①Cerebral infarction volume:No infarcts were found in hypertension group and sham operated group. On 1 day and 7 days after MCAO,the infarct volumes were increased gradually in model group,electric acupuncture group and fake acupuncture group〔infarct volumes on 1 day were(12.36±0.11)%, (12.19±0.15)%,(12.24±0.16)%,and on 7 days were(20.01±0.24)%,(19.54±0.61)%and(19.77±0.25)%, respectively〕,and on 14 days and 28 days after MCAO,the infarct volumes were decreased gradually〔infarct volumes on 14 days were(17.18±0.23)%,(16.96±0.11)%,(17.08±0.62)%,and on 28 days were(14.38±0.21)%, (13.95±0.46)% and(14.29±0.37)%,respectively〕,but the differences among three groups had no statistical significance(all P>0.05). ② Cortex area:On 1 day after MCAO,the differences in the cortical neuron numbers among all groups were not statistically significant(all P>0.05). On 7,14,28 days after MCAO,the cortical neuron number of sham operated group was more than that of hypertension group,but the difference had no statistical significance(all P>0.05). Compared with sham operated group,the cortical neuron number in model group began to increase significantly after 7 days;compared with model group,the cortical neuron number in electric acupuncture group was increased obviously(cell/HP,7 days:75.48±2.41 vs. 68.78±1.42,14 days:61.32±2.60 vs. 48.78±1.41,28 days:53.65±1.46 vs. 28.78±1.21,all P<0.05),while the cortex neuron number of fake acupuncture group was markedly reduced(7 days:67.75±1.43,14 days:47.50±1.25,28 days:27.50±1.25), but the differences had no statistical significance(all P>0.05).③Spinal cord area:On 1,7,14 days after MCAO, the differences of the spinal cord neuron numbers among all groups were not statistically significant(all P>0.05). On 28 days,compared with hypertension group,the cord neuron number of sham operated group was increased,but the difference had no statistical significance(P>0.05). Compared with model group,the cord neuron number in electric acupuncture and fake acupuncture groups was inecreased(cell/HP:21.32±1.60,16.17±1.05 vs. 15.02±1.18),the difference being statistical significant in electric acupuncture group(P<0.05)but no statistical significance in fake acupuncture group(P>0.05). Conclusions Generally,the secondary spinal(cervical part)neuron death occurs after cerebral infarction in rats. The therapeutic action of electric acupuncture may reduce the secondary spinal neuron damage at remote site after cerebral infarction,that is possibly the mechanism of electric acupuncture for the protection of brain in hypertensive rats from I/R injury.