Perchlorate inhibition of iodide uptake in normal and iodine-deficient rats.
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.
Paulus
Brian F
BF
Directorate of Toxicology, Health Effects Research Program, U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, Maryland 21010, USA.
Bazar
Matthew A
MA
Salice
Christopher J
CJ
Mattie
David R
DR
Major
Michael A
MA
D000818:Animals; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D007455:Iodine / Q000172:deficiency* / Q000493:pharmacokinetics*; D010472:Perchlorates / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013961:Thyroid Gland / Q000378:metabolism
D004785:Environmental Pollutants; D010472:Perchlorates; D007455:Iodine; C494474:perchlorate