照射抑制成年大鼠海马齿状回神经元再生的实验  

An experiment on irradiation-inhibited neuron regeneration in the hippocampal dentate gyrus of adult rats

作　　者：邱幸生[1] 陈龙华[1] 郭凌燕[2] 刘仕杰[2] 

机构地区：[1]南方医科大学附属南方医院放疗科,广东省广州市510515 [2]解放军第一五七医院信息科,广东省广州市510510

出　　处：《中国临床康复》2005年第40期62-64,共3页Chinese Journal of Clinical Rehabilitation

基　　金：国家自然科学基金资助(39870225)~~

摘　　要：目的:观察照射对成年大鼠海马齿状回神经元再生的影响。方法:实验于2004-05/2005-04在南方医科大学生理学教研室完成。选择成年雄性Wistar大鼠32只,随机分为对照组和照射组,每组16只。用6MV高能X射线行全脑照射10Gy后,灌注固定取脑,行组织学检查。照射后12h,用末端脱氧核苷酸转移酶介导的切口末端标记法检测海马齿状回凋亡细胞;照射后2个月,用神经巢蛋白免疫组织化学标记计数神经前体细胞,用5-溴脱氧尿苷标记法检测再生神经细胞数量,用5-溴脱氧尿苷与神经特异核蛋白双染法标记再生神经元,计数双染阳性细胞占5-溴脱氧尿苷单染阳性细胞数的比例。结果:32只实验动物照射过程中照射组与对照组因麻醉各死亡1只,30只进入结果分析。①正常大鼠海马齿状回颗粒下层基本无末端脱氧核苷酸转移酶介导的切口末端标记阳性细胞,照射后12h,可见该区域末端脱氧核苷酸转移酶介导的切口末端标记阳性细胞数量较对照组明显增加,差异有显著性[(0.25±0.46),(42.1±9.6)个/张,P<0.001]。②照射后2个月,神经巢蛋白的免疫组织化学标记结果表明,照射组大鼠海马齿状回神经巢蛋白阳性细胞数量与正常对照组接近,差异无统计学意义[(226.0±33.3),(195.0±39.1)个/张,P=0.11]。③5-溴脱氧尿苷与神经特异核蛋白双染标记显示,照射组5-溴脱氧尿苷与神经特异核蛋白双染阳性细胞占5-溴脱氧尿苷阳性细胞数比例较对照组显著降低[(12.8±5.0)%,(81.3±6.6)%,P<0.001],表明照射明显抑制再生神经细胞向神经元方向分化。结论:照射可选择性诱导大鼠海马齿状回神经增殖细胞凋亡,照射后2个月神经前体细胞数量无明显减少,而神经前体细胞增殖活性及向神经元方向分化均受到明显阻滞。AIM： To observe the effects of radiation on neuron regeneration of hippocampal dentate gyrus in adult rats. METHODS： The experiment was conducted at the Staff Room of Physiology, Southern Medical University from May 2004 to April 2005. Thirty-two adult male Wistar rats were assigned randomly into control group and radiation group with 16 rats in each group. The rats were subjected to whole brain irradiation with 6MV X-ray for 10 Gy, and then the brains were gained with perfusion, and to perform histology check. After radiation for 12 hours, the apoptosis in hippocampal dentate gyrus was detected with the cutting end labeling method mediated by terminal deoxynucleotidyl transferase. After radiation for 2 months, neural precursors were counted with neural nidogen immunohistochernistry labeling. Proliferating neural ceils were displayed with BrdU labeling method. The regeneration neurons were labeled with BrdU and neuron-specific nucleoprotein （NeuN） double staining. The proportion of double-stain positive cells in single-stain positive ceils of BrdU was counted. RESULTS： One rat died in radiation group and control group, respectively during the radiation in 32 experimental animals, because of anesthesia. Thirty rats were involved in the result analysis. ① After radiation for 12 hours, there were no cutting end labeling positive ceils mediated with terminal deoxynucleotidyl transferase at the low layer of hippocampal den tate gyrus granules in normal rats, but the number of cutting end labeling positive cells mediated with terminal deoxynucleotidyl transferase increased markedly as compared with the control group in that region, and the difference was significant [（0.25±0.46）, （42.1±9.6） each per piece, P〈0.001]. ② After radiation for 2 months, the results of immunohistochemistry labeling of neural nidogen showed that the number of positive ceils of neural nidogen in hippocampal dentate gyrus in rats of control group was close to that in the normal control group, and the difference had no s

关 键 词：神经再生 脑损伤 细胞凋亡 放射疗法 全脑照射 

分 类 号：R743[医药卫生—神经病学与精神病学]