RESUMO
OBJECTIVE: To observe the effect of electroacupuncture (EA) on learning-memory ability of vascular dementia (VD) rats, and the simultaneous changes of plasma and cerebral somatostatin (SS) and beta-endorphin (EP) contents. METHODS: Forty-one SD rats were randomly divided into control (n=8), model A (n=8, no treatment) and B (n=8, intragastric perfusion of 15% saline), EA (n=9) and medication (n=8, intragastric perfusion of Nimoldipine, 12 mg/kg) groups. VD model was established by using modified 4-vessels occlusion method. EA (150 Hz, 1-2 mA) was applied to "Baihui" (GV 20), "Dazhui" (DU 14), "Pishu" (BL 20) and "Shenshu" (BL 23) for 20 min, once daily for 15 days. Morris water maze tests were conducted for evaluating the rats' learning-memory ability. The contents of SS and beta-EP in plasma and brain tissue were measured by radioimmunoassay (RIA). RESULTS: In comparison with sham-operation group, the escape latency (EL) prolonged significantly and the target-platform crossing times decreased remarkably (P<0.01) in model group B. In comparison with model group B, EL shortened and target-platform crossing times increased both significantly in EA and medication groups (P<0.01). Plasma and cerebral SS, and cerebral beta-EP contents of model groups A and B were significantly lower than those of sham-operation group(P<0.01), while plasma beta-EP level had no obvious change (P>0.05). Plasma and cerebral SS, and cerebral beta-EP contents in both EA and medication groups were considerably higher than those in model groups A and B (P<0.01). No significant differences were found between EA and medication groups in EL, target-platform crossing times, plasma and cerebral SS and beta-EP levels, and between model group A and model group B in plasma and cerebral SS and beta-EP levels (P>0.05). CONCLUSION: EA can raise plasma and cerebral SS and cerebral beta-EP levels, and improve the learning-memory ability in VD rats.