Iodides are stored in the thyroid follicles mainly in the form of:
A. ThyroxineB. Thyroglobulin
C. Monoiodotyrosine
D. Diiodotyrosine
Answer
.B. Thyroglobulin
The thyroid gland
stores iodide primarily as thyroglobulin. The thyroid gland has a specialized
active transport system that very efficiently traps iodide from circulating
blood and can accumulate iodide against a large concentration gradient. Within
the thyroid, the iodide rapidly undergoes organification by which it is oxidized
and covalently linked to tyrosine residues in thyroglobulin. The iodinated
tyrosine residues gradually become coupled to form thyroxine, the major
secretion product of the thyroid.
