Is inhibition of thyroid hormone activation involved in methylmercury toxicity in the developing brain?

• Project/Area Number: 19510065
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Risk sciences of radiation/Chemicals
• Research Institution: Tohoku University
• Principal Investigator: YOSHIDA Katsumi Tohoku University, 大学院・医学系研究科, 教授 (90166942)
• Co-Investigator(Kenkyū-buntansha): MORI Kouki 東北大学, 大学院・医学系研究科, 准教授 (80301050)
• Project Period (FY): 2007 – 2009
• Project Status: Completed (Fiscal Year 2009)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2009: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2008: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2007: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: メチル水銀 / 甲状腺ホルモン / 脱ヨード酵素

Research Abstract

We examined the association of MeHg toxicity with deiodinases which regulate activation (D2) and inactivation (D3) of thyroid hormone by using cultured rat astrocytes or a human breasy cancer cell line MCF-7. MeHg significantly inhibited D2 and D3 activity. However, it did not affect the expression of D2 and D3 mRNA and protein. These results indicate that MeHg may disturb normal brain development through D2 and D3 inhibition.

Research Products

• [Journal Article] Effects of perinatal exposure to low-dose cadmium on thyroid hormone-related and sex hormone receptor gene expressions in brain of offspring. (2007)
  • Author(s): Ishitobi H
  • Journal Title: Neurotoxicology 28 Pages: 790-797
  • Peer Reviewed
• [Journal Article] Methylmercury inhibition of type II5'一deiodinase activity resulting in a decrease in growth hormone production in GH3 cells. (2007)
  • Author(s): Mori K
  • Journal Title: Toxicology 237 Pages: 203-209
  • Peer Reviewed
• [Presentation] メチル水銀のラット星状膠細胞における2型脱ヨード酵素活性および遺伝子発現に及ぼす影響 (2010)
  • Author(s): 岩瀬裕章、竹田真由、吉田克己、中川吉則、平林佐依子、尾崎泰、高橋友里恵、伊藤貞嘉、森弘毅
  • Organizer: 第53回日本甲状腺学会
  • Place of Presentation: 長崎
  • Year and Date: 2010-11-12
• [Presentation] 重金属の2型脱ヨード酵素遺伝子発現に及ぼす影響 (2010)
  • Author(s): 竹田真由、岩瀬裕章、森弘毅、尾崎泰、中川吉則、平林佐依子、伊藤貞嘉、吉田克己
  • Organizer: 第20回日本内分泌学会東北地方会
  • Place of Presentation: 仙台
  • Year and Date: 2010-04-24
• [Presentation] メチル水銀はアストロサイトの3型脱ヨード酵素遺伝子の発現を誘導する (2009)
  • Author(s): 半沢雄助、森弘毅、中川吉則、平林佐依子、尾崎泰、伊藤貞嘉、吉田克己
  • Organizer: 第25回甲状腺病態生理研究会
  • Place of Presentation: 東京
  • Year and Date: 2009-01-31
• [Presentation] メチル水銀はアストロサイトの3型脱ヨード酵素遺伝子の発現を誘導する (2009)
  • Author(s): 半沢雄助, 他
  • Organizer: 甲状腺病態生理研究会
  • Place of Presentation: 東京
  • Year and Date: 2009-01-31