Objective: To observe the effect of electroacupuncture (EA) on changes of ultrastructure and proliferation of astrocytes in the marginal zone of the cerebral ischemia locus in rats at different time courses so as to explore its underlying mechanism in the treatment of cerebral ischemia (CI).
Methods: Ninety Wistar rats were randomized into sham operation (sham), model and electroacupuncture (EA) groups which were further divided into 1 h, 1 d, 3 d, 7 d, and 21 d subgroups, with 6 cases in each. CI model was established by occlusion of the middle cerebral artery with heat-coagulation. EA (4/20 Hz, 2-3 V, 1-3 mA) was applied to "Baihui" (GV 20) and "Dazhui" (GV 14) for 30 min once daily. The ultrastructure changes of astrocytes were observed by using transmission electronic microscope, and glial fibrillary acidic protein (GFAP) expression of astrocytes was displayed by using immuno-fluorescent dyeing and observed under laser confocal scanning microscope (LCSM).
Results: Following CI, the astrocytes were swelling in structure and increased in number in CI model group, while compared with model group, the degree of swelling of astrocytes was decreased obviously in EA group. The mean fluorescence intensity values of GFAP on day 1, day 3, day 7 and day 21 post-modeling in model group increased significantly in comparison with sham group (P < 0.01), while those of GFAP from day 1 to day 21 post-modeling in EA group were significantly lower than those in model group (P < 0.01, P < 0.05), suggesting an inhibitory effect of EA on CI-induced upregulation of GFAP expression.
Conclusion: EA of GV 20 and GV 14 can relieve CI-induced ultrastructural injury of astrocytes in the rat, which is closely with its effect in inhibiting CI-induced overexpression of GFAP in astrocytes of the ischemic brain tissue.