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1、中國(guó)科技論文在線(xiàn)http://www.paper.edu.cn小鼠體內(nèi)硒對(duì)甲基汞毒性拮抗作用機(jī)制研#究**李玄,趙璐,張弛,王銳5(同濟(jì)大學(xué)環(huán)境科學(xué)與工程學(xué)院污染控制與資源化研究國(guó)家重點(diǎn)實(shí)驗(yàn)室,上海200092)摘要:汞污染是影響全球的重大環(huán)境問(wèn)題之一,由于汞(尤其是甲基汞)具有高生物累積性及不可降解的特點(diǎn),受汞污染地區(qū)的生物所面臨的健康風(fēng)險(xiǎn)將長(zhǎng)期存在。硒作為生物的必需元素,已被廣泛證實(shí)可以拮抗汞的毒性效應(yīng),然而其具體作用機(jī)制仍不明晰。本文選用Balb/c10小白鼠作為受試生物,設(shè)計(jì)甲基汞單一暴露及硒-甲基汞共暴露條件下的生物累積及排出實(shí)驗(yàn),從個(gè)體水平(生物累
2、積與組織分布)及分子水平(免疫器官的氧化/抗氧化平衡)兩個(gè)層面初步揭示小鼠體內(nèi)硒對(duì)甲基汞的解毒機(jī)制。實(shí)驗(yàn)發(fā)現(xiàn),富硒食物的添加可促進(jìn)小鼠體內(nèi)甲基汞的排出過(guò)程,顯著影響小鼠體內(nèi)甲基汞的分布,并降低靶器官(如免疫器官)中甲基汞的含量。此外,甲基汞暴露誘導(dǎo)了小鼠免疫器官(脾臟和胸腺)活性氧自由基(ROS)的15累積,降低了抗氧化能力,而食物硒的攝入則可幫助恢復(fù)免疫器官中的氧化還原平衡狀態(tài),從而消除汞毒性導(dǎo)致的細(xì)胞氧化損傷(脂質(zhì)過(guò)氧化和蛋白氧化)和細(xì)胞凋亡。關(guān)鍵詞:甲基汞;硒;拮抗作用;生物累積;毒性中圖分類(lèi)號(hào):X17120Investigatingthepossibl
3、emechanismsunderlyingtheprotectiveeffectsofseleniumonmethylmercury-inducedtoxicityinmiceLIXuan,ZHAOLu,ZHANGChi,WANGRui(StateKeyLaboratoryofPollutionControlandResourceReuse,CollegeofEnvironmental25ScienceandEngineering,TongjiUniversity200092)Abstract:Mercury(Hg)pollutionisoneofthemos
4、timportantenvironmentalproblemsworldwide.ThepotentialhealthrisksposedbyHgexposurealwaysexistforalongtime,sinceHg(especiallymethylmercury,MeHg)couldnotbedegradedandcouldbeeasilyaccumulatedinbiota.Asanessentialelement,selenium(Se)hasbeenwidelyverifiedtoprotectagainstHg-inducedtoxicity
5、,30however,theunderlyingmechanismisstillunclear.Inthepresentstudy,weconductedaseriesofbioaccumulationandeliminationexperimentsunderMeHgandSe-MeHgco-exposureconditions,usingBalb/cmiceasmodelorganism,tryingtoexplorethepossiblemechanismunderlyingtheprotectiveeffectsofseleniumagainstMeH
6、g-inducedtoxicityfrombothindividuallevel(bioaccumulationanddistribution)andmolecularlevel(theoxidative/antioxidativebalanceinimmune35organs).Ourresultsrevealedthat,dietarySesupplementationpromotedtheeliminationofMeHginmice,significantlyalteredtheMeHgdistributioninmicetissues,reduced
7、theMeHgburdeninthepotentialtoxicitytargetorgans(suchasimmuneorgans)ofmice.Besides,MeHgexposurepromotedthegenerationofthereactiveoxygenspecies(ROS),reducedthelevelsofantioxidantsinimmuneorgans(thymusandspleen),whiledietarySeadministrationrecoveredtheoxidative/antioxidative40balancein
8、immuneorgansanddimi