亚慢性砷暴露小鼠血和肝中砷形态及谷胱甘肽水平检测分析  

Determination. and evaluation of arsenic speciation and glutathione level in liver and blood of mice subchronically exposed to inorganic arsenic

作　　者：牛玉红[1] 曲春清[1] 钟媛[1] 于霄云[1] 李革新[1] 吕秀强[1] 孙贵范[1] 金亚平[1] 

机构地区：[1]中国医科大学公共卫生学院劳动卫生学教研室,沈阳110001

出　　处：《中国地方病学杂志》2008年第3期260-263,共4页Chinese Jouranl of Endemiology

基　　金：国家自然科学基金（30571590）

摘　　要：目的探讨亚慢性饮水砷暴露小鼠血和肝中砷形态的分布，评价砷对血和肝中还原型谷胱甘肽（GSH）水平的影响。方法小鼠以自由饮水方式饮用含砷量为0（对照）、25、50、100mg／L的水溶液，连续染砷6周。采用氢化物发生-超低温捕集-原子吸收分光光度法，检测小鼠血和肝中无机砷（iAs）、一甲基砷酸（MMA）和二甲基砷酸（DMA）的水平，计算甲基化率。采用二硫双硝基苯甲酸（DTNB）法测定全血和肝组织中GSH的水平。结果小鼠血和肝中iAs、MMA和DMA水平随染砷剂量的增加而升高。各染砷组小鼠血和肝中的砷一甲基化率（PMI）和二甲基化率（SMI）与对照组比较差异均有统计学意义（P〈0．05），其中50mg／L染砷组小鼠肝中SMI[（50．45±2．94）％]明显高于25mg／L组[（41．68±7．09）％]和100mg／L组[（41．19±8．87）％]，组间比较差异有统计学意义（P〈0．05）。各染砷组小鼠血和肝中砷形态的构成比（iAs：MMA：DMA）分别为2：3：5和4：3：3。有机砷（MMA＋DMA）的水平分别约占总砷的80％和60％。各染砷组小鼠血和肝中GSH水平随染砷剂量的增加而下降，与对照组比较差异均有统计学意义（P〈0．05），但各染砷组之间的小鼠血和肝中GSH水平比较差异均无统计学意义（P〉0．05）。结论当砷暴露水平达到一定程度后，肝脏对iAs的甲基化代谢能力可达到饱和。血中砷形态变化不同于肝组织，提示机体内的其他组织器官也可能具有砷甲基化代谢能力。血和肝中GSH水平是反映砷毒性的较好指标。Objective To explore the distribution of arsenic speciation and to estimate the effect of arsenic on glutathione （GSH） levels in the blood and liver of mice exposed to different concentrations of inorganic As^Ⅲ through drinking water. Methods Mice drank water containing arsenite at concentrations of iAs^Ⅲ of 0 （control）, 25, 50, 100 mg/L for 6 weeks. Blood and liver were sampled to assess the levels of inorganic arsenic （iAs）, monomethylarsenic acid （MMA）, dimethylarsenic acid （DMA） by the method of hydride generation trapping and ultra-hypothermia coupled with atomic absorption spectrometry, and the level of GSH by the method of 5,5′-Dithio-bis （2-Nitrobenzoic acid）. Results Levels of iAs, MMA and DMA in blood and in liver increased along with the increase of iAs concentrations in drinking water. Primary methylated index （PMI） and secondary methylation index （SMI） of liver and blood were significantly higher in exposed groups than those in control group（P 〈 0.05）. SMI of liver in 50 mg/L exposed group[ （50.45 ± 2.94）%] was significantly higher than those in 25 mg/L and 100 mg/L groups [ （41.68 ± 7.09）% and （41.19 ± 8.87 ）%, respectively], the difference being statistically significant（P 〈 0.05 ）. The ratio of iAs, MMA and DMAin blood and liver in exposed group were 2 ： 3 ： 5 and 4 ： 3 ： 3, the percentage of level of organic arsenic（MMA ＋ DMA） were 80% and 60%. GSH in blood and liver in exposed group decreased along with iAs concentrations in drinking water and had significant differences compared with those in control group （P 〈 0.05）. However, levels of GSH in liver and blood did not differ significantly between exposed groups and control group （P 〉 0.05 ）. Condusions Metabolism of iAs in liver is maximized when the iAs concentrations in drinking water increases to a certain level. However, the percentage of arsenic speciation in blood is different from that in liver, suggesting that other organs and tissues may be capabl

关 键 词：砷 谷胱甘肽 甲基化 

分 类 号：R686[医药卫生—骨科学]