Abstract
Radioactive iodide (131I−) protection studies have focused primarily on the thyroid gland and disturbances in the hypothalamic-pituitary-thyroid axis. The objective of the current study was to establish 131I− urinary excretion profiles for saline, and the thyroid protectants, potassium iodide (KI) and ammonium perchlorate over a 75 hour time-course. Rats were administered 131I− and 3 hours later dosed with either saline, 30 mg/kg of NH4ClO4 or 30 mg/kg of KI. Urinalysis of the first 36 hours of the time-course revealed that NH4ClO4 treated animals excreted significantly more 131I− compared with KI and saline treatments. A second study followed the same protocol, but thyroxine (T4) was administered daily over a 3 day period. During the first 6–12 hour after 131I− dosing, rats administered NH4ClO4 excreted significantly more 131I− than the other treatment groups. T4 treatment resulted in increased retention of radioiodide in the thyroid gland 75 hour after 131I− administration. We speculate that the T4 treatment related reduction in serum TSH caused a decrease synthesis and secretion of thyroid hormones resulting in greater residual radioiodide in the thyroid gland. Our findings suggest that ammonium perchlorate treatment accelerates the elimination rate of radioiodide within the first 24 to 36 hours and thus may be more effective at reducing harmful exposure to 131I− compared to KI treatment for repeated dosing situations. Repeated dosing studies are needed to compare the effectiveness of these treatments to reduce the radioactive iodide burden of the thyroid gland.
Highlights
Stable iodide (127I−), as potassium iodide (KI) or “dietary iodine”, has been recognized for over 30 years as a practical thyroid radioprotectant for people exposed to radioactive isotopes of iodide [1,2]
The objective of this study was to compare the relative efficacy of stable iodide and perchlorate to purge 131I− from the body of rats
We evaluated the efficacy of these post-exposure treatments by monitoring 131I− in the thyroid gland, urine, and serum for up to 3 days after dosing
Summary
Stable iodide (127I−), as potassium iodide (KI) or “dietary iodine”, has been recognized for over 30 years as a practical thyroid radioprotectant for people exposed to radioactive isotopes of iodide [1,2]. In a recent National Academies of Science report on the distribution and administration of KI in the event of a nuclear incident [3], sodium perchlorate (Irenat®) was recommended for adults if KI treatment was contraindicated, such as in patients with preexisting thyroid disease. Successful thyroid radioprotectant treatments, such as KI or ammonium perchlorate (NH4ClO4), are judged by their ability to block or limit thyroidal uptake of trace amounts of radioactive iodide (e.g., 131I−), while limited research has focused on treatment doses promoting excretion of the isotopes. The United States Food and Drug Administration (US FDA) recommends. The kinetic profile of 131I− in laboratory animals treated with
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Environmental Research and Public Health
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
