针灸对Aβ_(1-42)诱导阿尔茨海默病模型大鼠齿状回神经元及星形胶质细胞超微结构的影响

Effect of acupuncture on the ultrastructure of neurons and astrocytes in the hippocampal dentate gyrus in rats with Alzheimer's disease induced by Aβ_(1-42)

目的:观察针灸"百会""肾俞"穴对阿尔茨海默病(AD)模型大鼠海马齿状回超微结构的影响。方法:将40只SPF级雄性Wistar大鼠随机分为正常组、假手术组、模型组和针灸组,每组10只。模型组与针灸组均双侧海马各注射5μLβ淀粉样蛋白1-42(Aβ1-42)制备AD模型,假手术组注射等量0.9%NaCl溶液。针灸组于造模3 d后针灸"百会"及"肾俞"穴,每次20 min,每日1次,6 d为一疗程,连续治疗2个疗程,疗程间间隔1 d。其余各组常规饲养,不予干预。于造模前、造模后第4天、干预后进行水迷宫检测,记录大鼠逃避潜伏期、跨越平台次数,干预后取海马组织齿状回部位,用透射电镜观察大鼠海马齿状回神经元、星形胶质细胞超微结构的变化。结果:①造模后第4天,与正常组和假手术组比较,模型组平均逃避潜伏期明显延长,跨越平台次数明显减少(均P<0.01)。干预后,针灸组与模型组比较,平均逃避潜伏期缩短,跨越平台次数明显增加(均P<0.01)。②正常组和假手术组的神经元、星形胶质细胞形态均完整,核及膜结构清晰,线粒体、内质网及溶酶体等细胞器形态正常。模型组神经元形态较不规则、胞核严重固缩,胞质严重水肿,异染色质颜色加深,内质网扩张并脱颗粒,线粒体数目减少,甚可见线粒体嵴呈畸形样改变;星形胶质细胞周边严重水肿,胞质中少见细胞器,线粒体严重肿胀,内质网轻度扩张。针灸组神经元胞质和星形胶质细胞周边水肿仍较明显,线粒体轻度肿胀,但较模型组均有所减轻,且神经元内质网、核糖体未见明显异常。结论:针灸治疗有助于改善Aβ1-42诱导阿尔茨海默病大鼠海马齿状回神经元和星形胶质细胞的超微病理变化。

Objective To observe the effects of acupuncture at 'Baihui'(GV 20) and 'Shenshu'(BL 23) on the ultrastructure of hippocampal dentate gyrus in rats with Alzheimer’s disease. Methods Forty SPF Wistar male rats were randomly divided into a normal group, a sham operation group, a model group and an acupuncture group, 10 rats in each one. The rats in the model group and the acupuncture group were treated with injection of 5 μL Aβ1-42 at bilateral hippocampus, while the rats in the sham operation group were treated with injection of 5 μL 0.9% NaCl. Three days after modeling, the rats in the acupuncture group were treated with acupuncture at 'Baihui'(GV 20) and 'Shenshu'(BL 23)for 20 min, once a day, six treatments constituted a course, and totally two courses were given with an interval of 1 day between courses. The rats in the other groups received normal diet and no treatment was given. Before modeling, four days after modeling and after treatment, water maze test was performed to observe the escape latency and the number of crossing platforms. The hippocampal dentate gyrus was collected and transmission electron microscope was applied to observe the ultrastructure changes of neurons and astrocytes. Results ①Four days after modeling, compared with the normal group and the sham operation group, the escape latency was significantly prolonged and the number of crossing platforms was reduced in the model group(all P<0.01);after treatment, compared with the model group, the escape latency was significantly reduced and the number of crossing platforms was increased in the acupuncture group(both P<0.01). ②In the normal group and the sham operation group, the morphology of neurons and astrocytes was intact, the nuclear and membrane structure were clear, and the morphology of organelles such as mitochondria, endoplasmic reticulum and lysosomes was normal. In the model group, the morphology of neurons was irregular, the nucleus was severely constricted with edema in the cytoplasm, the color of heterochromatin was deepened, the endoplasmic reticulum was expanded, the granulation was removed and the number of mitochondria was decreased, even with malformed-like change in mitochondrial cristae;there was severe edema around astrocytes, few organelles in the cytoplasm, severe swelling of mitochondria and mild expansion of the endoplasmic reticulum. In the acupuncture group, the edema of the neuron and astrocytes was still evident, and the mitochondrial was mildly swollen but relieved compared with that in the model group, and there were no obvious abnormalities in neuronal endoplasmic reticulum and ribosomes. Conclusion Acupuncture could improve the ultrastructure of neurons and astrocytes in the hippocampal dentate gyrus in rats with Alzheimer’s disease induced by Aβ1-42.