Radioiodine tracers as useful tools in studies of thyrotoxic effects of exogenous bromide and perchlorate ions
With the use of 125I and 131I radionuclides, we followed the effects of exogenous bromide and perchlorate ions on the metabolism of iodine and of thyroid hormone in the rat. The presumed thyrotoxic effects of bromide and perchlorate have been confirmed and quantified. Correct assay conditions for the radiometric determination of the enzyme activity of thyroid peroxidase (TPO) have been established. The use of the adapted radiometric assay revealed a divergent influence of bromide and perchlorate ions on the TPO activity in the rat thyroids. Excessive bromide exerted a biphasic effect, depending on the extent of bromide intake in the animals. In contrast, in all the rats that were administered with high amounts of perchlorate were found elevated TPO activities.
KeywordsBromide Perchlorate Radioiodine tracer Thyroid hormone
This work was supported by the Ministry of Education of the Czech Republic (Research Project No. MSM0021622413), by the Academy of Sciences of the Czech Republic (Research Project No. AV0Z50110509), and by the Czech Science Foundation (GA CR Grant No. 304/08/0256).
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