Perchlorate Inhibition of Iodide Uptake in Normal and Iodine-deficient Rats

摘要

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 ~(131)I 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 ~(131)I 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 ~(131)I in the iodine-deficient rats.