摘要
目的观察慢性镉中毒对小鼠海马齿状回颗粒层细胞结构的影响。方法将清洁级4~5月龄昆明种小鼠40只随机分为对照组与镉中毒组,每组20只,雌雄各半。适应性饲养1周后,镉中毒组采用皮下注射氯化镉（2 mg/kg）,每周2次,连续染毒3个月,对照组同时注射等体积生理盐水。连续喂养3个月后取大脑海马组织分别进行尼氏染色、胶质纤维酸性蛋白（GFAP）、神经元特异性烯醇酶（NSE）免疫组化染色和透射电镜观察。结果光镜下,尼氏染色与免疫组化染色结果显示,对照组小鼠海马齿状回颗粒层神经元排列整齐、规则,结构完整,胞体较大,细胞轮廓清楚,胞核居中、核仁明显、胞浆尼氏体丰富,均匀分布于核周;胶质细胞分散在海马神经元之间,呈星形或梭形,体积小、核圆形或卵圆形;镉中毒组小鼠海马齿状回颗粒层神经元胞体变小、胞核固缩、胞浆减少,尼氏体明显减少或消失、着色浅,胶质细胞分散在海马神经元之间,体积增大;与对照组相比,镉中毒组海马齿状回颗粒层胶质细胞与NSE阳性神经元的数量增多（P〈0.05）。电镜下,对照组海马齿状回颗粒层神经元形态规则,胞膜清晰,细胞器丰富,结构完整;镉中毒组神经元胞体轻度水肿,核膜皱褶,核染色质皱缩,胞浆密度降低,细胞器减少,线粒体肿胀,部分透明成空泡。结论慢性镉中毒可导致小鼠海马齿状回颗粒层神经元减少、星型胶质细胞增多,这些变化可能是镉的神经毒性作用之一。
Objective To observe the morphological changes in granule cell layer on astrocytes and neurons in the hippocampal dentate gyrus（DG） of mice with chronic cadmium poisoning.Methods Forty Kunming mice（4-5 months old） of clean grade were randomly divided into two groups,20 in each and half of females and males.The rats in cadmium-exposed group were injected subcutaneously with cadmium（CdCl2,2.0mg/kg,twice a week） for 3 consecutive months,while those in normal control group were injected with equate saline.After 3 months the structure of DG was observed under the light microscope,and quantitative analysis was made by morphometric technique.Simultaneously,the ultrastructural changes in DG were observed under the transmission electron microscope.Results The results of Nissl staining and immunohistochemical staining showed that the neurons in DG of control group mice were arranged regularly,with intact structure,larger cell body,distinct cell circumscription,the central nucleus,obvious nucleolus,abundant Nissl bodies and cytoplasm distributed evenly around the nucleus.Astrocytes were scattered among the neurons,showing star or spindle shape,with small,round or oval nucleus,but the neurons in cadmium-exposed group had smaller cell body,karyopycnosis,reduced cytoplasm within ranging from the size and number of acidophilia granula;Nissl bodies were decreased significantly or even disappeared,with superficial coloration.Compared with that in control group,the number of neuron-specific enolase（NSE）-positive neurons and astrocytes in cadmium poisoning group was increased（P0.05）.Under the electron microscope,neurons in control group had regular morphology,clear membrane,abundant organelles and structural integrity;the neurons in cadmium poisoning group had mild swelling,folded nuclear membrane,shrunknuclear chromatin,decreased cytoplasmic density,fewer organelles,swollen mitochondria,some of them were transparent or even became vacuolus.Conclusion Chronic cadmium poisoning in mice may lead to reduction of DG neurons and increase of astrocytes,which might be one of the mechanisms of neurotoxicity of cadmium.
出处
《西安交通大学学报（医学版）》
CAS
CSCD
北大核心
2011年第2期180-183,共4页
Journal of Xi’an Jiaotong University（Medical Sciences）
基金
国家自然科学基金资助项目(No.30660189)
2009年度贵州省社会发展科技攻关计划项目(黔科合SY字[2009]3058)
贵阳医学院青年教师基金资助项目(K2007-61
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关键词
镉中毒
海马
齿状回
神经元
星形胶质细胞
小鼠
cadmium poisoning
hippocampus
dentate gyrus
neuron
astrocyte
mouse
