Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, 060-0818, Japan.
Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, 060-0818, Japan; Water Research Group, School of Environmental Sciences and development, North-West University, South Africa.
Environ Pollut. 2019 Sep;252(Pt B):1267-1276. doi: 10.1016/j.envpol.2019.05.038. Epub 2019 May 9.
Metal pollution has been associated with anthropogenic activities, such as effluents and emissions from mines. Soil could be exposure route of wild rats to metals, especially in mining areas. The aim of this study was to verify whether soil exposure under environmentally relevant circumstances results in metal accumulation and epigenetic modifications. Wistar rats were divided to three groups: 1) control without soil exposure, 2) low-metal exposure group exposed to soil containing low metal levels (Pb: 75 mg/kg; Cd: 0.4), and 3) high-metal exposure group exposed to soil (Pb: 3750; Cd: 6). After 1 year of exposure, the metal levels, Pb isotopic values, and molecular indicators were measured. Rats in the high-group showed significantly greater concentrations of Pb and Cd in tissues. Higher accumulation factors (tissue/soil) of Cd than Pb were observed in the liver, kidney, brain, and lung, while the factor of Pb was higher in the tibia. The obtained results of metal accumulation ratios (lung/liver) and stable Pb isotope ratios in the tissues indicated that the respiratory exposure would account for an important share of metal absorption into the body. Genome-wide methylation status and DNA methyltransferase (Dnmt 3a/3b) mRNA expressions in testis were higher in the high-group, suggesting that exposure to soil caused metal accumulation and epigenetic alterations in rats.
金属污染与人为活动有关，如矿山的废水和废气排放。土壤可能是野生老鼠接触金属的途径，特别是在矿区。本研究旨在验证在与环境相关的情况下，土壤暴露是否会导致金属积累和表观遗传修饰。Wistar 大鼠被分为三组：1）无土壤暴露的对照组，2）低金属暴露组，暴露于含低金属水平的土壤中（Pb：75mg/kg；Cd：0.4），3）高金属暴露组，暴露于土壤中（Pb：3750；Cd：6）。暴露 1 年后，测量了金属水平、Pb 同位素值和分子指标。高组大鼠组织中 Pb 和 Cd 的浓度明显更高。在肝脏、肾脏、大脑和肺部，Cd 的积累因子（组织/土壤）高于 Pb，而 Pb 的积累因子在胫骨中更高。金属积累比（肺/肝）和组织中稳定 Pb 同位素比值的获得结果表明，呼吸暴露将占金属吸收到体内的重要份额。睾丸中的全基因组甲基化状态和 DNA 甲基转移酶（Dnmt3a/3b）mRNA 表达在高组中更高，表明土壤暴露导致大鼠金属积累和表观遗传改变。
