Intrathyroidal iodine metabolism in the rat. The iodotyrosines

Abstract

It is usual to regard thyroxine biosynthesis as occurring in five stages: (i) accumulation of iodide by the thyroid gland; (ii) oxidation of iodide to iodine; (iii) iodination of tyrosine, yielding mono- iodotyrosine; (iv) iodination of monoiodotyrosine, yielding di-iodotyrosine; (v) coupling of two mole- cules of di-iodotyrosine. Stages (iii), (iv) and (v) are generally supposed to take place within the thyro-