Accumulation of Excessive Doses of Iodide by the Thyroid Gland of Normal, Hypophysectomized and Thyroxine-treated Rats

Abstract

THE accumulation of iodide by the thyroid gland is customarily measured subsequent to the administration of radioiodide and is expressed either as ‘thyroid iodide uptake’ (as a percentage of the administered dose) or as ‘thyroid: serum radioiodide concentration ratio’ (T/S ratio). The literature related to this subject-matter has been amply reviewed by Halmi¹ and more recently by Wolff². Both these authors make it clear that besides thyrotrophin (TSH), other factors, such as dietary iodine for example, play an important part in the regulation of thyroidal iodine metabolism. This communication reports work dealing with the accumulation of inorganic iodide by the thyroid gland of animals subjected to various types of treatment and injected with doses of iodide large enough to practically block the organification of the accumulated iodide².