基于MRI的铅暴露老年大鼠脑铁研究  

Effect of lead exposure on brain iron in aged rats based on the MRI

作　　者：黎砚书[1] 陈英[1] 焦欢[1] 周繁坤[1] 杜桂花[1] 冯昶[1] 闫冀[2] 刘征华[3] 肖新兰[3] 范广勤[1] 

机构地区：[1]南昌大学公共卫生学院,南昌330006 [2]南昌大学医学院医学实验教学部 [3]南昌大学第二附属医院

出　　处：《卫生研究》2013年第1期33-38,共6页Journal of Hygiene Research

基　　金：国家自然科学基金(No.30960324;81273120;21267017);江西省自然科学基金(No.2009GZY0138)

摘　　要：目的探讨长期铅暴露对老年大鼠脑组织中铁含量的影响。方法 SPF级SD雌性和雄性大鼠分别随机分为3组:空白组(0g/L醋酸铅溶液)、低剂量组(0.8g/L醋酸铅溶液)、高剂量组(1.5g/L醋酸铅溶液),按3∶2合笼,空白组所生雄性仔鼠自由饮用去离子水,低剂量组所生雄性仔鼠给予0.3g/L的醋酸铅溶液即0.3g/L染铅组,高剂量组所生雄性仔鼠给予0.9g/L的醋酸铅溶液即0.9g/L染铅组,继续染毒饲养至老年(18月)后,GE MR 3.0T磁共振扫描仪对活体大鼠脑铁行定量分析,ICP-AES测量血液及离体大脑组织中铅和铁元素的含量和经灌注后观察海马神经元超微结构。结果与空白组相比,铅暴露组血铅及脑铅含量增加(P<0.05),0.9g/L染铅组脑铁及皮层、海马、丘脑铁含量均显著增加(P<0.05),且大鼠血、大脑及皮层、海马、丘脑中铁含量与血铅呈高度正相关。电镜结果提示,随着染铅剂量增加,胞质、胞核、线粒体结构和突触结构均遭到不同程度的破坏,出现早期神经元细胞凋亡现象。结论铅暴露引发老年大鼠铁过载,铅诱发的神经退行性病变可能与其引发铁过载有关。Objective To explore the effect of long-term lead exposure on brain iron in aged rats. Methods SPF female and male Sprague-Dawley rats were respectively randomly divided into three groups： control, low lead-exposed, high lead-exposed. Lead-exposed female rats drank 0.8g/L or 1.5g/L lead acetate solutions through pregnancy until weaning and then the pups received 0. 3g/L or 0. 9g/L lead acetate solution depending on their group. Control group rats drank deionized water throughout the experiment. At the postnatal 18 months, one pup for per group was given an ultra structural detection of hippocampus, and the other male pups were measured the lead and iron concentration of blood and brain by GE MR 3.0T MR scanner and ICP-AES. Results In comparing with control group, the lead concentrations of blood and brain in lead-exposed groups were significantly higher, andthe iron contents of brain and cortex, hippocampus, thalamus were significantly higher in 0. 9g/L lead-exposed group. Also, it was highly positively correlated between blood lead and iron of blood, cortex, hippocampus, thalamus, respectively. With the dose of leadexposed increased, cytoplasm, nucleus, mitochondrial structure and synaptic structure had suffered vary degrees of damage from ultra structural detection of hippocampus, it could be observed early neuronal apoptosis. Conclusion Lead induced neurodegenerative diseases might be related to iron overload which caused by lead exposure.

关 键 词：铅暴露 磁共振 铁 神经退行性病变 

分 类 号：R994.6[医药卫生—毒理学] Q593.2[医药卫生—药学]