Sexual differences in neuroprotective effect and brain fragility by mouse brain sex hormones

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K00569
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Risk sciences of radiation and chemicals
• Research Institution: Hiroshima University
• Principal Investigator: Yamazaki Takeshi 広島大学, 統合生命科学研究科(総), 教授 (30192397)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: メチル水銀 / アクアポリン / 酸化ストレス

Outline of Final Research Achievements

Methyl mercury chloride was orally administered to ICR mice. Administration of half the amount of methylmercury that causes typical toxicity in mice induced oxidative stress, activation of astrocytes, protein expression of aquaporin and edema, specifically in periaqueductal gray matter. The amount of mercury accumulated in this region was similar to that in the cerebral cortex and cerebellum, where the effects of methylmercury toxicity were not observed. These results revealed that the periaqueductal gray matter was particularly vulnerable to methylmercury. We are currently investigating the relationship between sex steroid hormones and sex differences in toxicity to this new toxicity and other neurotoxicity.

Free Research Field

生化学

Academic Significance and Societal Importance of the Research Achievements

水銀はいまだにかなりの量が環境に放出されており，メチル水銀によるヒトの低濃度汚染のリスクは続いている。一方，水俣病の原因が明らかになって60年以上経過した現在でも，メチル水銀による脳障害のメカニズムやその性差には不明な点が多い。この研究では，低用量のメチル水銀による新規の脳神経毒性が見出された。これはマウスでの結果であるが，ヒトの低濃度汚染の影響部位の予想にも，哺乳類の神経毒性の性差のメカニズム解明にも寄与する研究成果である。