Objective To observe the effect of electroacupuncture(EA)on CD 34+endothelial progenitor cells(EPCs)in bone marrow and peripheral blood and the expression of p-AKT protein in bone marrow in focal cerebral ischemia/reperfusion(CI/R)rats

so as to investigate its mechanism underlying improvement of cerebral ischemia.Methods A total of 108 male SD rats were randomly divided into sham operation(sham)group

model(CI/R)group

and EA group which were further divided into12

24

48hsubgroups(n=12/group

6rats for biochemical analysis and the other 6rats for Western blot analysis).CI/R model was established by occlusion of the right middle cerebral artery for 2hours followed by reperfusion.EA(2Hz/20Hz)was applied to"Baihui"(GV 20)

left"Hegu"(LI 4)and left"Taichong"(LR 3)acupoints for 30 min

once daily.The neurological deficit scores were evaluated using Longa 5-grade standards.Flow cytometer was used to detect the percentages of CD 34+EPCs in bone marrow and peripheral blood.The expression of p-AKT protein of bone marrow was detected by Western blot.Results In comparison with the CI/R model group

the neurological deficit score were gradually and significantly decreased 48 hafter CI/R in the EA group(P<0.05)

suggesting an improvement of the neurological function after EA.Compared with the sham group

the percentages of CD 34+EPCs in bone marrow and peripheral blood and the expression level of bone-marrow p-AKT protein were significantly up-regulated in the model group at the three time-points after CI/R(P<0.01

P<0.05).Following EA intervention

the percentages of CD 34+EPCs at the three time-points in the peripheral blood

and at time-points of 12 hand 24hin the bone marrow

and the expression levels of p-AKT protein at the three time-points were significantly further up-regulated in the EA group in comparison with the model group(P<0.05

P<0.01).Conclusion EA can effectively up-regulate the percentages of CD 34+EPCs in the bone marrow and peripheral blood

and increase p-AKT protein expression in the bone marrow in CI/R rats

which may contribute to its effect in improving neurological function.