2022 Fiscal Year Final Research Report

A Novel Mechanism of Genetic Mutation Independent Metal Tolerance in a Multi-Hierarchical Terrestrial Organism Population Using High Precision XAFS

Research Project

PDF

Project/Area Number	20K20633
Research Category	Grant-in-Aid for Challenging Research (Pioneering)
Allocation Type	Multi-year Fund
Review Section	Medium-sized Section 63:Environmental analyses and evaluation and related fields
Research Institution	Hokkaido University
Principal Investigator	NAKAYAMA Shouta 北海道大学, 獣医学研究院, 准教授 (90647629)
Co-Investigator(Kenkyū-buntansha)	藤森崇龍谷大学, 先端理工学部, 准教授 (20583248) 中田北斗北海道大学, 獣医学研究院, 博士研究員 (60815273) 銅谷理緒北海道大学, 獣医学研究院, 学術研究員 (00934415)
Project Period (FY)	2020-07-30 – 2023-03-31
Keywords	金属耐性機構 / 動物種差 / 毒性発現 / XAFS解析
Outline of Final Research Achievements	In order to elucidate the mechanisms in terrestrial animals, where toxic effects do not become apparent even after exposure to high concentrations of lead (Pb), we have focused on the analysis of the chemical speciation of lead and sulphur and applied XAFS analysis at the Large Synchrotron Radiation Facility in the field of environmental toxicology and achieved results. For the first time, precise knowledge was obtained on the differences in lead forms in the liver, kidney, heart, brain, lungs, spleen, muscle, stomach, small and large intestine contents and faeces of wild rats,lizards, chickens and dogs, and on the changes in lead chemical forms when absorbed into the digestive system and the body. The spectra were similar to those of lead bound to thiol groups, reflecting the important role of the liver in the detoxification/excretion mechanism of heavy metals via molecules such as glutathione.
Free Research Field	毒性学、環境毒性学
Academic Significance and Societal Importance of the Research Achievements	鉛の高濃度蓄積による毒性影響が発現しない個体における耐性機構解明のために、スペクトルに結合元素や酸化状態ごとに違いが現れやすい硫黄にも着目して解析を行うことで、微細な構造に着目する必要のある鉛のスペクトル解析から得られた暴露経路の推定を補強できることが明らかになった。この手法は他の動物種や地域の研究でも応用可能であり、世界規模で問題となっている金属汚染における汚染経路解明の新たな手法としての応用が期待される。