(Table 1) Concentration of PCB and other contaminants in blood plasma of polar bears (Ursus maritimus) from Svalbard ...

• Main Authors: Gutleb, Arno C, Cenijn, Peter, Van Velzen, Martin, Lie, Elisabeth, Ropstad, Erik, Janneche Utne Skaare, Malmberg, Tina, Bergman, Åke, Gabrielsen, Geir W, Legler, Juliette
• Format: Dataset
• Language: English
• Published: PANGAEA - Publishing Network for Geoscientific and Environmental Data 2010
• Subjects: Arctic; Svalbard; Ursus maritimus
• Online Access: https://dx.doi.org/10.15468/4urteg; https://www.gbif.org/dataset/587c2944-a368-4e65-948a-a2c2f067865a

Persistent chemicals accumulate in the arctic environment due to their chemical reactivity and physicochemical properties and polychlorinated biphenyls (PCBs) are the most concentrated pollutant class in polar bears (Ursus maritimus). Metabolism of PCB and polybrominated biphenyl ether (PBDE) flame-retardants alter their toxicological properties and these metabolites are known to interfere with the binding of thyroid hormone (TH) to transthyretin (TTR) in rodents and humans. In polar bear plasma samples no binding of [125I]-T4 to TTR was observed after incubation and PAGE separation. Incubation of the plasma samples with [14C]-4-OH-CB107, a compound with a higher binding affinity to TTR than the endogenous ligand T4 resulted in competitive binding as proven by the appearance of a radio labeled TTR peak in the gel. Plasma incubation with T4 up to 1 mM, a concentration that is not physiologically relevant anymore did not result in any visible competition. These results give evidence that the binding sites on ...