头穴丛刺法对慢性脑缺血大鼠海马血管内皮生长因子表达的影响

目的:观察头穴丛刺法对慢性脑缺血大鼠认知功能和海马血管内皮生长因子(VEGF)表达的影响,探讨头针抗慢性脑缺血的可能机制。方法:32只大鼠采用改良的双侧颈总动脉永久性结扎法制备慢性脑缺血模型,造模成功的大鼠分为模型组、头穴丛刺组和尼莫地平组,另设8只大鼠为假手术组。头穴丛刺组于术后第5周起,取"百会"和"百会"左右旁开2mm 3个穴位针刺,留针30min,每日1次,治疗4周。尼莫地平组于术后第5周起给予尼莫地平灌胃,每天1次,治疗4周。治疗结束后采用Morris水迷宫检测大鼠的认知功能;HE染色,光镜下观察海马细胞形态变化;免疫组化法检测海马VEGF蛋白表达。结果:术后8周,模型组、头穴丛刺组和尼莫地平组大鼠逃避潜伏期较假手术组明显延长(P<0.05);头穴丛刺组和尼莫地平组与模型组相比,逃避潜伏期缩短(P<0.05)。头穴丛刺组和尼莫地平组变性的神经细胞较模型组明显减轻。模型组、头穴丛刺组、尼莫地平组均可见VEGF蛋白表达增高,与假手术组比较差异有统计学意义(P<0.05);头穴丛刺组和尼莫地平组VEGF表达较模型组升高(P<0.05)。结论:头穴丛刺能够明显改善大鼠的认知功能,可能是通过上调VEGF蛋白表达,从而对慢性脑缺血后新生血管的形成具有促进作用,进而促进神经元恢复。

Effect of Scalp Acupuncture on Learning Ability and Hippocampal VEGF Expression in Chronic Cerebral Ischemia Rats

Objective To observe the effect of scalp cluster-needle intervention on cognitive ability and hippocampal vascular endothelial growth factor(VEGF) expression in cerebral ischemia(CI) rats.Methods Forty Wistar rats were rando-mized into sham operation(sham),model,scalp-acupuncture and medication groups.Chronic CI model was established by occlusion of the bilateral common carotid arteries.Acupuncture needles were inserted into "Baihui"(GV 20) and its left and right points(2 mm beside GV 20) and manipulated leftward and rightward for 3 min at a frequency of about 200 times/min,retained for 30 min.The treatment was conducted once daily,for 4 weeks.For rats of the medication group,Nimodipine(1 mg/kg) was gi-ven to the animal by gavage,once a day,for 4 weeks.The rats' learning ability was measured by Morris water maze.Changes of hip-pocampal cellular morphology were observed by HE staining and light microscope,and hippocampal VEGF expression was detected by immunohistochemistry.Results In comparison with the sham group,the escape latency of rats in the model group was prolonged significantly(P<0.05),suggesting a decrease of learning ability after CI.Compared with the model group,the escape latency of both acupuncture and medication groups were reduced markedly after the treatment(P<0.05).In comparison with the sham group,the number of VEGF immunoreaction(IR) positive cells in the model group was up-regulated significantly(P<0.05),while compared with the model group,the numbers of both acupuncture and medication groups were increased further(P<0.05).No significant differences were found between the acupuncture and medication groups in escape latency and VEGF expression levels(P>0.05).HE staining showed that in the model group the hippocampal pyramidal cells were reduced in number,became vaguer in layers and nucleole,and got deformed in structure with karyopycnosis and disappearance of endochylema,and cavitation.These situations were relatively lighter in both acupuncture and medication groups.Conclusion Scalp acupuncture intervention can significantly improve CI rats' congnitive ability and pathological changes,which may be related to its function in increasing the expression of VEGF in the hippocampus.