Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA.
Environ Health Perspect. 2010 Feb;118(2):242-8. doi: 10.1289/ehp.0900956.
Many populations are exposed to multiple species of mercury (Hg), predominantly organic Hg as methylmercury (MeHg) from fish, and inorganic Hg as Hg vapor from dental amalgams. Most of our knowledge of the neurotoxicity of Hg is based on research devoted to studying only one form at a time, mostly MeHg.
In this study we investigated the effects of prenatal exposure to MeHg and Hg vapor on Hg concentrations in the brain of neonatal rats.
Female Long-Evans hooded rats were exposed to MeHg (0, 3, 6, or 9 ppm as drinking solution), Hg vapor (0, 300, or 1,000 microg/m3 for 2 hr/day), or the combination of both, from 30 days before breeding through gestational day 18. On postnatal day 4, whole brains were taken from one male and one female from each of four litters in each treatment group to assess organic and inorganic Hg in the brain by cold vapor atomic absorption spectrometry.
Statistical analysis using linear mixed effects models showed that MeHg dose was the primary determinant of both organic and inorganic brain Hg levels. For both outcomes, we also found significant interactions between MeHg and Hg vapor exposure. These interactions were driven by the fact that among animals not exposed to MeHg, animals exposed to Hg vapor had significantly greater organic and inorganic brain Hg levels than did unexposed animals.
This interaction, heretofore not reported, suggests that coexposure to MeHg and Hg vapor at levels relevant to human exposure might elevate neurotoxic risks.
许多人群接触到多种汞（Hg）物种，主要是来自鱼类的有机汞（甲基汞，MeHg）和来自牙合金的无机汞（Hg 蒸气）。我们对 Hg 神经毒性的大部分了解都是基于一次只研究一种形式的研究，主要是 MeHg。
在这项研究中，我们研究了母体暴露于 MeHg 和 Hg 蒸气对新生大鼠大脑中 Hg 浓度的影响。
雌性长冠褐家鼠从受孕前 30 天到妊娠第 18 天，通过饮用含 0、3、6 或 9ppm MeHg 的溶液或暴露于 0、300 或 1000μg/m3 的 Hg 蒸气（每天 2 小时），接受 MeHg 和 Hg 蒸气暴露。在出生后第 4 天，从每组四个幼鼠中各取一雄一雌两只，取其全脑，采用冷蒸气原子吸收光谱法测定脑内有机和无机 Hg 的含量。
采用线性混合效应模型的统计分析表明，MeHg 剂量是大脑中有机和无机 Hg 水平的主要决定因素。对于这两种结果，我们还发现 MeHg 与 Hg 蒸气暴露之间存在显著的相互作用。这些相互作用的原因是，在未暴露于 MeHg 的动物中，暴露于 Hg 蒸气的动物的脑有机和无机 Hg 水平明显高于未暴露的动物。
这种相互作用以前没有报道过，表明在与人类暴露相关的水平下，同时暴露于 MeHg 和 Hg 蒸气可能会增加神经毒性风险。
