针刺拮抗弱视剥夺效应与脑源性神经营养因子相关性的研究

目的:从亚细胞病理学、免疫组织化学角度,开展针刺拮抗弱视剥夺效应与脑源性神经营养因子相关性的研究,揭示针刺拮抗弱视剥夺效应的作用机制。方法:选用4周龄健康幼猫18只,采用单侧眼睑缝合的方法建立剥夺性弱视动物模型。动物随机分为正常组、模型组、治疗组,每组6只。模型组不做任何治疗;治疗组于术后第1 d开始,取“睛明”“承泣”“球后”“攒竹”穴进行针刺治疗,各穴交替使用,每日1次,10次为1疗程,疗程间隔2 d,治疗9个疗程。治疗结束后,各组动物均进行超微结构观察和免疫组化研究。结果:模型组视皮质神经元出现退行性病变。治疗组可不同程度地改善上述状况。模型组动物视皮质、外侧膝状体、视网膜神经节细胞脑源性神经营养因子(BDNF)的数密度分别为(138.3±23.12),(38.91±18.43),(4.43±2.01)×102/mm2,积分光密度分别为(0.78±0.38),(0.86±0.30),(1.03±0.32)/μm2,与正常组比较BDNF数量和活性明显降低(P<0.01),而治疗组具有显著的上调作用(P<0.01)。结论:针刺可逆转剥夺所造成的神经元退变,有利于神经元传导功能的恢复及突触传递的重建。针刺对剥夺效应的拮抗作用是通过影响神经营养因子的合成和分泌来实现的。

Study on the Correlation between the Deprivation Effect of Resisting Amblyopia of Acupuncture and Brain Derived Neurotrophic Factor

Objective: To study the correlation of deprivation effect of acupuncture against amblyopia and brain derived neurotrophic factor for revealing its relative mechanism.Methods: Eighteen young cats(4 weeks old) were averagely randomized into normal control,model and acupuncture groups.Amblyopia model was established by suturing unilateral eyelids.One day after operation,for rats of acupuncture group,"Jingming"(BL 1),"Chengqi"(ST 1),"Qiuhou"(EX-HN 7),and "Cuanzhu"(BL 2) were punctured,once daily,16 weeks altogether.At the end of experiments,the cats were killed for taking tissues of visual cortical Area 17,lateral geniculate body and retina.These tissues were then embedded with Epon812 epoxy resin and cut into sections and stained with immunohistochemical technique.Ultrastructural changes of the neurons were observed with transmission electronic microscope and the integral optical density(IOD) values,numerical density(ND) of immuno-reaction positive cells were detected.Results: Marked retrograde degeneration of visual cortical neurons(irregular shape of the nuclear membrane,shrinkage and vacuolar degeneration of mitochondria,derangement of mitochondrial crista,irregularity of synaptic vesicles,enlargement of synaptic gaps,etc) was found in model group,while that in acupuncture group lightened at different degrees. In comparison with normal control group,the values of ND and IOD of brain derived neurotrophic factor(BDNF) in visual cortex,lateral geniculate body and retinal ganglion cells were obviously lowered,while those values of ND and IOD of acupuncture group were significantly higher than those of model group(P<0.01);no significant differences were found between normal control and acupuncture groups in these two indexes.It indicated that acupuncture could inhibit unilateral eyelid suture induced neuronal retrograde degeneration of the visual cortex and down-regulation of BDNF expression in amblyopia cats.Conclusion: Acupuncture can prevent visual deprivation induced ultrastructural injury of the visual cortical neurons,which may be partially related to upregulation of BDNF expression.