百草枯和代森锰慢性暴露对小鼠黑质纹状体多巴胺能系统的影响  

Effects of Paraquat and Maneb on System of Substantial Nigra and Striatum in Mice

作　　者：王广鹤[1] 何德富[1] 许海燕[1] 

机构地区：[1]华东师范大学环境科学系,上海200062

出　　处：《环境与健康杂志》2009年第7期590-592,F0003,共4页Journal of Environment and Health

摘　　要：目的研究农药百草枯(praquat,PQ)和代森锰(maneb,MB)单独和(或)联合暴露对小鼠黑质致密部(substanitial nigra compact,SNc)脑区多巴胺(dopamine,DA)能系统的影响,并探讨其与帕金森症(Parkinson’sdisease,PD)发病的关系。方法将120只健康清洁级5周龄昆明小鼠随机分为对照(生理盐水)组、PQ(5mg/kg)组、MB(15mg/kg)组、PQ(5mg/kg)+MB(15mg/kg)组,每组30只。采用腹腔注射方式进行染毒,染毒剂量为10ml/kg,每周染毒2次,连续染毒16周。采用爬杆试验和开阔试验检测小鼠运动行为的变化,对SNc区域进行组织病理学观察和神经元细胞计数。以荧光分光光度法检测纹状体(Caudateputamen,CPu)脑区中DA的含量。结果各组动物体重间比较,差异均无统计学意义(P>0.05)。染毒前和染毒8、16周后,各组小鼠的爬杆时间和跨格数间比较,差异均无统计学意义(P>0.05)。与对照组比较,染毒8、16周后PQ+MB组小鼠中脑SNc区神经元呈现胞体固缩样退化形态,细胞数量显著减少(P<0.01);而PQ组和MB组无显著性变化(P>0.05)。与对照组比较,染毒16周后第1天仅PQ+MB组小鼠纹状体脑区DA含量较高,差异有统计学意义(P<0.01);而PQ组和MB组小鼠纹状体脑区DA含量无显著性变化(P>0.05)。结论单独PQ或MB低剂量长期暴露对SNc脑区的神经元无影响,二者低剂量联合暴露可导致SNc神经元损伤和丢失,表明PQ和MB的协同神经毒性可能与帕金森症发病有关。Objective To investigate the effects of paraquat （PQ）,maneb （MB） or their combined exposure on neurons of substanitial nigra compact in mice,and to research the relationship between pesticides and Parkinson＇s disease. Methods One hundred and twenty Kunming mice aged five weeks were randomly divided into 4 groups： control group（saline）,PQ group（5 mg/kg）, MB group （15 mg/kg） and PQ （5 mg/kg）＋MB （15 mg/kg）group,30 in each. Mouse was treated with the pesticides through intraperitoneal injection （10 ml/kg）,twice a week for 16 consecutive weeks. Spontaneous behaviors were examined by using the pole test and open field test. Histopathological examination was done and neurons were counted in substantia nigra compact. The dopamine concentration in candate putamen （CPu） were analyzed by fluorescencespectrophotometry. Results No significant average body weight change was observed among groups and no significant difference was observed in the time of pole test and the times of crossing grids between exposed groups and control group （P〉0.05） before administration and after 8 weeks and 16 weeks of administration. Cell pyknosis and neurodegeneration in substantial nigra were observed in the PQ＋MB group for 8 weeks and 16 weeks （P〈0.01）. Compared with the control group,only the PQ＋MB group showed increased DA concentration in CPu at the first day after 16 weeks of administration （P〈0.01）. Conclusion Chronic exposure to low-dose PQ or MB may not induce SNc neurons damage in mice. However, chronic exposure to PQ and MB in combination can cause neurons damage and neuron loss in SNc, which clues that synergetic neurotoxic effect of PQ and MB may be involved in Parkinson＇ s disease.

关 键 词：农药 百草枯 代森锰 帕金森症 多巴胺 黑质纹状体 

分 类 号：R994.6[医药卫生—毒理学]