title: Differences in the responses of three plasma selenium-containing proteins in relation to methylmercury-exposure through consumption of fish/whales.
abstract: 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.
authors.affiliation: 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.
authors.forename: Ping Han
authors.initials: PH
authors.lastname: Ser
authors.affiliation: 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.
authors.forename: Sanae
authors.initials: S
authors.lastname: Omi
authors.affiliation: 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.
authors.forename: Hana
authors.initials: H
authors.lastname: Shimizu-Furusawa
authors.affiliation: National Institute for Minamata Disease, Hama, Minamata City, Kumamoto Prefecture, 867-0008, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yasutake
authors.affiliation: National Institute for Minamata Disease, Hama, Minamata City, Kumamoto Prefecture, 867-0008, Japan.
authors.forename: Mineshi
authors.initials: M
authors.lastname: Sakamoto
authors.affiliation: National Institute for Minamata Disease, Hama, Minamata City, Kumamoto Prefecture, 867-0008, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Hachiya
authors.affiliation: 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; Department of Anthropology, University of Washington, Box 353100, Seattle WA98195-3100, USA.
authors.forename: Shoko
authors.initials: S
authors.lastname: Konishi
authors.affiliation: National Institute for Minamata Disease, Hama, Minamata City, Kumamoto Prefecture, 867-0008, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: 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. Electronic address: chiho@humeco.m.u-tokyo.ac.jp.
authors.forename: Chiho
authors.initials: C
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D015415:Biomarkers / Q000097:blood; D001798:Blood Proteins / Q000378:metabolism*; D015930:Diet Records; D005247:Feeding Behavior; D005260:Female; D005399:Fishes; D020387:Food Chain; D005506:Food Contamination; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D007564:Japan; D008297:Male; D008767:Methylmercury Compounds / Q000009:adverse effects* / Q000097:blood; D008875:Middle Aged; D017747:Seafood; D051149:Selenoprotein P / Q000097:blood*; D011795:Surveys and Questionnaires; D015854:Up-Regulation; D014874:Water Pollutants, Chemical / Q000009:adverse effects* / Q000097:blood; D014907:Whales
chemical_list: D015415:Biomarkers; D001798:Blood Proteins; D008767:Methylmercury Compounds; D051149:Selenoprotein P; D014874:Water Pollutants, Chemical; D005979:Glutathione Peroxidase
keywords: Fish consumption; Glutathione peroxidase; Methylmercury; Selenium; Selenoprotein P