氚宫内照射对大鼠神经细胞分布及脑机能的影响  

Effects of irradiation in utero from tritiated water on the distribution of neural cells and brain function in rats

作　　者：姚晓波[1] 王永生[1] 邱俊 吴翠萍[3] 陶新全[4] 王明明[1] 

机构地区：[1]安徽医科大学临床医学院放射医学研究所,合肥230032 [2]安徽省第二人民医院MRI室,合肥230001 [3]肥东县人民医院呼吸科,合肥230001 [4]蚌埠医学院第一附属医院核医学科,蚌埠233004

出　　处：《安徽医科大学学报》2014年第10期1371-1375,共5页Acta Universitatis Medicinalis Anhui

基　　金：国家自然科学基金(编号:81273003);安徽省自然科学基金(编号:1208085MH162);安徽省教育厅自然科学基金(编号:KJ2011Z162);安徽省教学质量工程项目(编号:2010941)

摘　　要：目的探讨氚水宫内照射对仔鼠脑神经细胞迁移和脑机能的影响。方法雌性SD大鼠孕龄第10天（ E10）一次性腹腔注射3.7＆#215;106 Bq/（ g体液）氚水，孕龄E18及出生后当天（ P0）取部分仔鼠脑标本，用免疫组织化学法检测大脑皮质神经细胞黏附分子NCAM、L1表达情况，观察氚β射线内照射对神经细胞迁移的影响；出生后38-42 d龄利用Morris水迷宫测量氚β辐射对仔鼠脑机能的影响；P90利用氢质子磁共振波谱（1H-MRS）检测仔鼠大脑内N-乙酰天门冬氨酸（NAA）及胆碱类化合物（Cho）分别与肌酸类化合物（ Cr）比值，分析氚辐射引发脑神经细胞与神经胶质细胞分布的改变。结果①免疫组织化学分析表明，与对照比较， E18及P0受照鼠脑内神经细胞黏附分子NCAM、L1的表达量均减小（ P〈0.05）；② Morris水迷宫检测显示，受照鼠逃避潜伏期较对照明显延长（ P〈0.05）；空间探索试验中，受照鼠在平台象限停留时间明显低于对照（P〈0.05）；③1H-MRS检测显示，受照鼠脑中 NAA/Cr比值较对照明显降低（P〈0.05），两组间Cho/Cr比值的差异无统计学意义（P〉0.05），表明氚β射线照射改变了脑内神经细胞与神经胶质细胞的相对比例，即辐射影响了脑内细胞分布。结论氚水宫内照射可下调仔鼠脑内与神经细胞迁移相关的神经细胞黏附分子NCAM、L1的表达，妨碍神经细胞正常迁移，导致脑内神经细胞分布异常，诱发仔鼠脑机能障碍。Objective To explore the effects ofβirradiation in utero from tritiated water on the distribution of neu-ral cells and brain function in rats. Methods Pregnant adult Sprague-Dawley rats were irradiated withβrays from tritiated water （HTO, 3.7＆#237;106 Bq/g body fluid） by a single intraperitoneal injection on the 10th day of gestation （ E10 ） . Brain specimens from rat offsprings were collected on the 18 th day of gestation （ E18 ） and postnatal day 0 （ P0 ） . The expression of neural cell adhesion molecule NCAM and L1 in cerebral cortex was assayed with immuno-cytochemical staining to study effects of beta radiation from HTO on neuronal migration in offsprings. Morris water maze was used to detect the changes of brain function during P38~P42 . The proton magnetic resonance spectrosco-py （ 1 H-MRS） was used to measue the ratio of Cho/Cr （ choline/creatine） and NAA/Cr （ N-acetyl aspartate/crea-tine） in cerebral cortex on P90 to analyse the distribution of neural cells. Results Compared with control, the ex-pression of neural cell adhesion molecule NCAM and L1 in brains of experimental offsprings（E18 and P0）was sig-nificantly reduced （ P 〈0.05 ） . The escape latency of experimental offsprings was significantly prolonged （ P 〈0.05 ） . The swimming time in the quadrant of platform was obviously shortened in the probe trial （ P〈0.05 ） . The ratio of NAA/Cr in experimental group was significantly decreased （ P〈0.05 ） and there was no difference between Cho/Cr ratios in two groups （ P〉0 . 05 ） . Conclusion The results suggest that HTO irradiation in utero could in-duce brain disfunction and disturb the distribution of neuronal cells in offspring. The mechanisms may be related to the downregulation of neural cell adhesion molecule NCAM and L1 .

关 键 词：氚水 电离辐射 神经细胞迁移 MORRIS水迷宫 氢质子磁共振波谱 

分 类 号：R811.5[医药卫生—放射医学]