title: Protective effects of selenium on mercury induced immunotoxic effects in mice by way of concurrent drinking water exposure.
abstract: Selenium (Se) has been recognized as one key to understanding mercury (Hg) exposure risks. To explore the effects of Se on Hg-induced immunotoxicity, female Balb/c mice were exposed to HgCl2- or MeHgCl-contaminated drinking water (0.001, 0.01, and 0.1 mM as Hg) with coexisting Na2SeO3 at different Se/Hg molar ratios (0:1, 1/3:1, 1:1 and 3:1). The potential immunotoxicity induced by Na2SeO3 exposure alone (by way of drinking water) was also determined within a wide range of concentrations. After 14 days' exposure, the effects of Hg or Se on the immune system of Balb/c mice were investigated by determining the proliferation of T and B lymphocytes and the activity of natural killer cells. Hg exposure alone induced a dose-dependent suppression effect, whereas Se provided promotion effects at low exposure level (<0.01 mM) and inhibition effects at high exposure level (>0.03 mM). Under Hg and Se coexposure condition, the effects on immunotoxicity depended on the Hg species, Se/Hg ratio, and exposure concentration. At low Hg concentration (0.001 mM), greater Se ingestion exhibited stronger protective effects on Hg-induced suppression effect mainly by way of decreasing Hg concentrations in target organs. At greater Hg concentration (0.01 and 0.1 mM), immunotoxicity induced by Se (>0.03 mM) became evident, and the protective effects appeared more significant at an Se/Hg molar ratio of 1:1. The complex antagonistic effects between Se and Hg suggested that both Se/Hg molar ratio and concentration should be considered when evaluating the potential health risk of Hg-contaminated biota.
authors: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China.
authors: Xuan
authors: X
authors: Li
authors: Daqiang
authors: D
authors: Yin
authors: Jiang
authors: J
authors: Li
authors: Rui
authors: R
authors: Wang
mesh_terms: D000818:Animals; D060766:Drinking Water / Q000737:chemistry*; D004784:Environmental Monitoring; D005260:Female; D000922:Immunotoxins / Q000737:chemistry / Q000633:toxicity*; D008628:Mercury / Q000737:chemistry / Q000633:toxicity*; D051379:Mice; D020011:Protective Agents / Q000737:chemistry*; D012643:Selenium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D060766:Drinking Water; D000922:Immunotoxins; D020011:Protective Agents; D014874:Water Pollutants, Chemical; D008628:Mercury; D012643:Selenium