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Perchlorate inhibition of iodide uptake in normal and iodine-deficient rats

Brian F Paulus1, Matthew A Bazar, Christopher J Salice

  • 1Directorate of Toxicology, Health Effects Research Program, U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, Maryland 21010, USA.

Journal of Toxicology and Environmental Health. Part A
|June 15, 2007
PubMed

Perchlorate-induced inhibition of thyroidal iodide uptake was measured in normal and iodine-deficient female Sprague-Dawley rats. Rats that were made iodine-deficient by long-term restriction of iodine in the diet absorbed a gavage dose of 131I to the thyroid in proportionally greater amounts than rats fed a normal diet. Furthermore, the iodine-deficient rats maintained their high rates of absorption even when challenged by levels of perchlorate in their drinking water sufficient to produce pronounced inhibition of 131I uptake in rats fed a normal diet. Every dose of perchlorate used in this study (1.1, 5.6, and 28 mg/L) produced significant inhibition of iodide uptake in normally fed rats, but only the highest level of perchlorate (28 mg/L) significantly inhibited thyroidal uptake of 131I in the iodine-deficient rats. Taken together, these results demonstrate that iodide-deficient animals exhibit increased resistance to the inhibition of iodine absorption resulting from perchlorate exposure.

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