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

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.