Ser Ping Han, Omi Sanae, Shimizu-Furusawa Hana, Yasutake Akira, Sakamoto Mineshi, Hachiya Noriyuki, Konishi Shoko, Nakamura Masaaki, Watanabe Chiho
Department of Human Ecology, School of International Health, Graduate School of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033, Japan.
National Institute for Minamata Disease, Hama, Minamata City, Kumamoto Prefecture, 867-0008, Japan.
Toxicol Lett. 2017 Feb 5;267:53-58. doi: 10.1016/j.toxlet.2016.12.001. Epub 2016 Dec 15.
Putative protective effects of selenium (Se) against methylmercury (MeHg) toxicity have been examined but no conclusion has been reached. We recently reported the lack of serious neurological symptoms in a Japanese fish-eating population with high intakes of MeHg and suggested a potential protective role for Se. Here, relationships between levels of Hg and Se in the blood and plasma samples, with a quantitative evaluation of Se-containing proteins, obtained from this population were examined. While levels of the whole-blood Hg (WB-Hg) and plasma Se (P-Se) showed a positive correlation, stratified analysis revealed that they correlated only in samples with higher (greater than the median) levels of MeHg. A food frequency questionnaire showed that consumption of fish/whales correlated with WB-Hg, but not with P-Se, suggesting that the positive correlation between WB-Hg and P-Se might not be the result of co-intake of these elements from seafood. Speciation of plasma Se revealed the differences in the responses of two plasma selenoproteins, glutathione peroxidase (GPx) and selenoprotein P (SePP), in relation to Hg exposure. In the high-Hg group, SePP showed a positive correlation with WB-Hg, but GPx did not. In the low-Hg group, neither SePP nor GPx showed any correlation with WB-Hg. These observations suggest that the increase in P-Se in the high-Hg group might be associated with an increase in SePP, which may, in turn, suggest an increased demand for one or more selenoproteins in various organs, for which SePP supplies the element.
人们已对硒（Se）对甲基汞（MeHg）毒性的潜在保护作用进行了研究，但尚未得出结论。我们最近报告称，在一个摄入大量MeHg的日本食鱼人群中未发现严重的神经症状，并提出了Se的潜在保护作用。在此，我们研究了从该人群获取的血液和血浆样本中汞（Hg）和Se水平之间的关系，并对含硒蛋白质进行了定量评估。虽然全血Hg（WB-Hg）和血浆Se（P-Se）水平呈正相关，但分层分析显示，它们仅在MeHg水平较高（高于中位数）的样本中相关。一份食物频率问卷显示，鱼类/鲸鱼的消费量与WB-Hg相关，但与P-Se无关，这表明WB-Hg和P-Se之间的正相关可能不是这些元素从海鲜中共同摄入的结果。血浆Se的形态分析揭示了两种血浆硒蛋白，即谷胱甘肽过氧化物酶（GPx）和硒蛋白P（SePP），在Hg暴露方面的反应差异。在高Hg组中，SePP与WB-Hg呈正相关，但GPx没有。在低Hg组中，SePP和GPx均与WB-Hg无任何相关性。这些观察结果表明，高Hg组中P-Se的增加可能与SePP的增加有关，这反过来可能表明各个器官对一种或多种硒蛋白的需求增加，而SePP为这些器官提供该元素。
