[Induction of free radicals after dietary exposure by mercury contaminated rice and protective effect of coexisting selenium].
Sprague-Dawley rats were reared by environmental mercury contaminated rice to survey the potential health risk of Wanshan mercury mining area. Electron spin resonance (ESR) was introduced to detect the species and the intensities of free radicals, using spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). The results showed that the mercury-contaminated rice significantly increased the levels of free radicals and MDA in rat brain at 7 days (p < 0.05). ESR spectrums showed that the principal spin adducts resulted from the trapping of alkyl free radical (alphaH = 22.7 x 10(-4)T +/- 1.6 x 10(-4)T, alphaN = 15.5 x 10(-4)T +/- 0.5 x 10(-4)T), and hydroxyl radical. Levels of free radicals and MDA increased slowly until after 90-day exposure period (83%, 100%). Element correlation analysis showed high correlations of mercury and selenium in the brain of rat fed with Wanshan rice, suggesting that the coexisting selenium in rice exhibited antagonistic effects on both mercury accumulation and toxicity. The slight increases of free radicals in rat brain at 7, 20 and 30-day exposure periods should be related with the scavenger effect of Se.
Ji
Xiu-ling
XL
School of Environmental Science and Engineering, Donghua University, Shanghai 200051, China. ling-jx@dhu.edu.cn
Cheng
Jin-ping
JP
Wang
Wen-hua
WH
Qu
Li-ya
LY
Zhao
Xiao-xiang
XX
Zhuang
Hui-sheng
HS
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D005506:Food Contamination; D005609:Free Radicals / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D008628:Mercury / Q000378:metabolism* / Q000633:toxicity; D008906:Mining; D012275:Oryza / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012643:Selenium / Q000378:metabolism* / Q000494:pharmacology
D005609:Free Radicals; D008315:Malondialdehyde; D008628:Mercury; D012643:Selenium