摘要
目的探讨锰对小鼠黑质GSH（glutathione）合成相关酶γ-GCS（γ-glutamylcysteine synthetase）和GSS（glutathione synthetase）的影响,为锰中毒机制的研究提供依据。方法小鼠64只,雌雄各半,依体重随机分为4组,每组16只,第1组为对照组,第2~4组分别为低、中、高剂量染锰组。第1组腹腔注射0.9%氯化钠,第2~4组分别腹腔注射12.5、25、50 mg/kg Mn Cl2,注射剂量为5 ml/kg,每天染毒1次,持续2周。最后一次染毒24 h后,将小鼠用水合氯醛麻醉后快速处死,冰浴条件下分离脑组织并取黑质;HE染色和透射电镜观察黑质组织形态及超微结构,Neu N和GFAP荧光双染观察神经元和星形胶质细胞分布及数量变化,试剂盒检测黑质内GSH含量,Western blotting法检测γ-GCS和GSS蛋白水平。结果随着各组染锰浓度升高,黑质组织形态和超微结构损伤逐渐加剧;免疫荧光发现胶质细胞增多,神经元减少;黑质内GSH水平下降,中剂量染锰组下降了53.82%,高剂量染锰组下降了68.36%;γ-GCS和GSS蛋白表达水平下降,其中γ-GCS在中、高剂量染锰组分别下降了7.8%、28.9%,GSS在中、高剂量染锰组分别下降了12.94%、32.94%。结论锰可通过干扰GSH合成相关酶γ-GCS和GSS的表达,影响GSH的合成,产生神经毒性。
Objective To explore the effect of manganese on GSH synthesis-related enzymes γ-GCS and GSS in mice substantia nigra,thereby provide experimental basis for further study on the toxic mechanism of manganese. Methods Sixty-four mice（ half male and half female） were randomly divided into 4 groups according to body weight,the first was control group,the mice were i. p injected with normal saline once a day for 2 weeks; while the second to fourth groups were manganese exposed groups,the mice were i. p injected with 12. 5,25 and 50 mg / kg Mn Cl2 respectively,the volume of injection was 5 ml / kg,once a day for 2 weeks. 24 hours later after last injection,all mice were rapidly killed by decapitation after anesthetized,separate brain tissues and take substantia nigra. HE staining for morpghological observation of substantia nigra,Neu N and GFAP double fluorescence staining for ultrastructural observation on neurons and astrocytes of substantia nigra was observed by electron microscopy. Content of GSH was measured by kit,γ-GCS and GSS detection by western blotting. Results The results showed that with the increase of Mn exposed level,the injury extent both in morphology and ultrastructure,the glial cell numbers were all increased in substantia nigra; the content of GSH decreased significantly, by 53. 82% in medium-dose Mn group and68. 36% in high-dose Mn group; γ-GCS and GSS expression also decreased,the γ-GCS expression was decreased by 7. 8% in medium-dose Mn group and 28. 9% in high-dose Mn group,and the GSS expression was decreased by 12. 94% in medium-dose Mn group and 32. 94% in high-dose group. Conclusion Manganese might affect the synthesis of GSH in substantia nigra,then induce neurotoxicity by disturbed the expression of γ-GCS and GSS.
出处
《中国工业医学杂志》
CAS
2015年第6期406-409,474,F0003,共6页
Chinese Journal of Industrial Medicine
基金
国家自然科学基金资助项目(项目编号:81302406)
