Objective To observe the influence of electroacupuncture(EA) of "Hegu"(LI 4) on blood stromal cell-derived factor 1α(SDF-1α)

CXC chemokine receptor 4+(CXCR 4+) positive cells and endothelial progenitor cells(EPCs) and bone marrow(BM) EPCs levels in local cerebral ischemia/reperfusion injury(CI/IR) rats

so as to study its mechanisms underl-ying improvement of cerebral ischemia.Methods A total of 54 SD rats were randomly divided into normal control

model

and EA groups.The latter two groups were further divided into 1 d

2 d

3 d and 7 d subgroups(4 time-points)

respectively.CI/RI model was established by occlusion of the middle cerebral artery.EA(40 Hz/60 Hz

1-2 mA) was applied to bilateral "Hegu"(LI 4) for 15 min

once daily

1

2

3 and 7 days

respectively.Flow cytometer was used to detect the counts of EPCs and CXCR 4+ cells in the peripheral blood

and BM EPCs.Serum SDF-1α was detected by enzyme linked immunosorbent assay(ELISA).Results Compared with the normal control group

the percentages of blood EPCs and CXCR 4+ cells and BM EPCs

and serum SDF-1α content on the 1st day

and the percentage of blood CXCR 4+ cells on the 2nd day were increased significantly in the model group(P<0.01

P<0.05).In comparison with the model group

percentages of blood EPCs and CXCR 4+ cells on the 1st day of EA group were reduced significantly(P<0.01)

but the percentage of blood EPCs on the 2nd day

those of blood CXCR 4+ cells on the 2nd day and 3rd day

serum SDF-1α content on the 2nd day

and the percentage of BM EPCs on the 2nd day in the EA group were all up-regulated significantly(P<0.05

P<0.01).No significant differences were found among the 3 groups in blood EPCs percentages on the 3rd day and 7th day

in blood SDF-1α content and BM EPCs percentage on the 7th day(P>0.05).Conclusion Generally

2 days' EA of LI 4 can up-regulate the percentages of blood and BM EPCs and blood CXCR 4+ cells as well as blood SDF-1α protein content in CI/RI rats

which may contribute to its effect in improving cerebral ischemia.