Objective To observe the effect of electroacupuncture(EA)pretreatment on the number of survival neurons and the expression of glucose regulated protein 78(GRP 78)and growth arrest and DNA damage-inducible gene 153(GADD 153)in the hippocampus in rats with global cerebral ischemia/reperfusion injury(CI/R)

so as to study its underlying mechanism in neuroprotective action.Methods SD male rats were randomly divided into 3groups(n=48each):sham operation

CI/R model and EA pretreatment group.Global CI/R model was induced by 4-vessel occlusion(bilateral vertebral artery cauterization and bilateral carotid artery ligation for 5min

followed by reperfusion).Before modeling

EA pretreatment of"Baihui"(GV 20)and"Dazhui"(GV 14

2Hz/15 Hz

1mA)was given to rats of the EA pretreatment group for 30 min

once daily for 5days.At 6

12

24 and 48hafter CI/R

the hippocampus tissues of rats in different subgroups were separately sampled to be stained with H.E.method for detecting the number of the survived neurons

stained with TUNEL method for assaying the apoptotic neurons in the CA 1region

and processed with Western blot(WB)for assaying the expression of GRP 78 and GADD 153 proteins.ResultsCompared with the sham group

the number of hippocampal survival neurons was significantly decreased at the time-points of12 h

24hand 48 hafter CI/R in the model group(P<0.05)and was apparently increased by EA pretreatment at 24 hand 48h(P<0.05).The number of the apoptotic neurons in the hippocampal CA 1region at the time-points of 6h

12 h

24hand 48 hafter CI/R was significantly bigger in the model group than in the sham group(P<0.05)

and was obviously decreased at 12 h

24h

48 hafter CI/R in the EA pretreatment group(P<0.05).WB detection showed that the expression levels of hippocampal GRP 78 and GADD 153 proteins at the four time-points after CI/R were significantly higher in the model group than in the sham group(P<0.05).Compared with the model group

hippocampal GRP 78 protein expression levels at the 4time-points were further markedly up-regulated(P<0.05)

while GADD 153 protein expression levels at the 4time-points were significantly suppressed in the EA pretreatment group(P<0.05).Conclusion EA pretreatment can effectively suppress the number of hippocampal apoptotic neurons and increase survival rate of neurons in CI/R rats

which may be closely associated with its effects in up-regulating the expression of GRP 78 protein and down-regulating the expression of GADD 153 protein in the hippocampus.