RESUMO
OBJECTIVE: To observe the influence of electroacupuncture (EA) of "Hegu" (LI 4) on blood stromal cell-derived factor 1alpha (SDF-1alpha), 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 underlying 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-1alpha 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-1alpha 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-1alpha 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-1alpha 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-1alpha protein content in CI/RI rats, which may contribute to its effect in improving cerebral ischemia.