RESUMO
OBJECTIVE: To observe the effect of electroacupuncture (EA) on serum lipid and cerebral neurogrowth factor (NGF) in rats with hyperlipemia and cerebral ischemia (CI). METHODS: A total of 36 SD rats were evenly randomized into control, model, EA-I and EA-II groups with 9 cases in each group. Hyperlipemia plus CI model was established by feeding the rats with high-fat foodstuff (6 weeks) and FeCI3-evoked middle-cerebral-artery (MCA) occlusion method. EA (15 Hz, 1-3 mA) was applied to "Sanyinjiao" (SP 6) and "Fenglong" (ST 40) for 20 min, once daily, continuously for 7 days, additionally,"Baihui" (GV 20) and "Shuigou"(GV 26) were punctured and stimulated with hand, which was conducted first before MCA occlusion for rats of group EA-I and after MCA occlusion for rats of group EA-II separately. Fasting blood samples (2 mL/rat) were taken for detecting serum total cholesterol (TC), triglyceride (TG), low density lipid cholesterol (LDL-C) and high density lipid cholesterol (HDL-C) levels. After decapitation of the rats, cerebral tissues were taken, homogenated for detecting NGF content with ABC-ELISA (enzyme-linked immunosorbent assay) and some other cerebral tissues were cut into sections (6 microm)for observing structural changes of the brain after staining with haematoxylin and cosin (HE) method. RESULTS: Compared with control group, serum TC, TG and LDL-C contents of model, EA-I and EA-II groups increased significantly on day 42 and 59 after modeling (P < 0.01), and HDL-C content of model, EA-I and EA-II groups decreased markedly on day 42 after modeling (P < 0.01). Compared with model group, TC contents of both EA-I and EA-II groups, and TG and LDL-C of EA-I group decreased significantly on day 59 after establishing the model (P < 0.05, 0.01). No significant differences were found between EA-I and EA-II groups in the 4 indexes of blood lipid (P > 0.05). HE staining showed that in model group, neuronal ischemic injury including cellular swelling, edema and nuclear fragmentation in the striatum and the cortex of parietal lobe, widening of the cellular interspace. vacuolation, irregularity of the kytoplasm and karyolemma, etc in CA3 region of hippocampus was apparent, while the situation in EA groups was lighter. Regarding the changes of NGF, compared with control group, NGF contents of model group and EA-I group were significantly lower (P < 0.01); while compared with model group, NGF content of EA-I was significantly higher (P < 0.01); and that of EA-lI group was markedly lower than that of EA-I group (P < 0.05). CONCLUSION: EA can lower the levels of serum TC, LDL-C and TG and suppress cerebral ischemia plus hyperlipemia induced decrease of NGF level in the brain, which may contribute to its effect in relieving ischemic cerebral injury.
