Accumulation features and blood-brain transfer of organohalogen metabolites in mammals and effects on thyroid hormones homeostasis

2015 Fiscal Year Final Research Report

• Project/Area Number: 25701014
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Environmental risk control and evaluation
• Research Institution: Ehime University
• Principal Investigator: Nomiyama Kei 愛媛大学, 沿岸環境科学研究センター, 准教授 (30512686)
• Co-Investigator(Renkei-kenkyūsha): TANABE Shinsuke 愛媛大学, 沿岸環境科学研究センター, 教授 (60116952) ; KUNISUE Tatsuya 愛媛大学, 沿岸環境科学研究センター, 教授 (90380287)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 有機ハロゲン化合物 / 水酸化代謝物 / 体内動態 / 脳 / 蓄積 / 甲状腺ホルモン / 毒性 / 野生生物

Outline of Final Research Achievements

Wildlife are chronically exposed of and bioaccumulate environmental contaminants such as PCBs and PBDEs, as well as their metabolic products (OH-PCBs and OH-PBDEs). A part of OH-PCBs and OH-PBDEs congeners structurally resemble thyroid hormones which are essential for normal brain development. Over the past decade, in vitro and in vivo studies on rodents and human epidemiological studies have been revealed the link between the exposure of OH-PCBs and/or OH-PBDEs and effects on the brain function and development. However, there are only few reports on the levels of the hydroxylated metabolites in the brains of terrestrial and marine mammals.
In this study, residual levels and patterns of PCBs, PBDEs, OH-PCBs and OH-PBDEs in the blood and brain of finless porpoises, dog, cat and Japanese monkey. The levels in the brain were compared to the laboratory determined effect threshold levels of OH-PCBs and OH-PBDEs, and possible effects on the wildlife are discussed.

Free Research Field

環境化学