环境汞污染暴露下大鼠肝中一氧化氮及一氧化氮合酶的变化

Changes of nitric oxide and nitric oxide synthetase in rat liver after exposure to environmental mercury

为了探讨汞污染暴露对公众健康的潜在危害,采用清镇化工地区汞污染粮食对大鼠进行暴露试验,研究不同暴露时间节点处大鼠肝中一氧化氮(NO)和一氧化氮合酶(NOS)的变化,并以市售上海粮食作对照。结果表明,利用汞污染的粮食对大鼠暴露7d后,大鼠肝中NO含量及NOS活力出现显著升高(p<0.05).7～30d暴露与长时间暴露90d情况相比,肝中NO含量相对稳定.对大鼠肝中汞、硒元素的分析表明,汞、硒元素含量间有相关关系(r=0.9426),表明硒元素对汞的毒性作用有一定影响.长期暴露90d后,肝中NO含量出现急剧上升,与对照组相比上升200%.同时,体内脂质过氧化产物丙二醛(MDA)含量也出现显著升高(p<0.05),表明长期暴露引起了机体的氧化损伤.

In order to survey the potential health risk of environmental exposure to mercury, Sprague-Dawley rats were reared on wastewater-contaminated rice from the Qingzhen area. Changes of nitric oxide （NO） and nitric oxide synthetase （NOS） in rat liver were examined after different exposure periods. The results showed that, compared with the controls, levels of NO and NOS in rat liver significantly increased after 7 days exposure to mercury-contaminated rice （p 〈0.05）. However, when compared with the long-term exposure group, the content of NO in rat liver changed only slightly during the 7 to 30 day exposure periods. Element correlation analysis showed high correlations of mercury and selenium in the liver of rats fed with Qingzhen rice （r = 0. 9426）, suggesting that the coexisting selenium in rice reduced the negative effects on mercury toxicity. After 90 days exposure, NO in rat liver increased 200%, and the peroxide MDA in rat liver also increased significantly （p 〈 0.05 ） , indicating aggravated oxidative status in rat liver after long-term exposure to environmental mercury.