The Measurement of the Iodine-Accumulating Function of the Human Thyroid Gland

At least two distinct mechanisms appear to be responsible for accumulation of iodine by the thyroid gland. The first, called the "iodide trap" by Vanderlaan and Vanderlaan (1), involves the concentration, presumably within the thyroid cells, of inorganic iodide obtained from the circulating blood. The second, called hormonal synthesis, involves the utilization of the trapped iodide for the synthesis of organic iodine compounds (chiefly diiodotyrosine and thyroxine) which are then stored in the colloid in thyroglobulin. Vanderlaan and Vanderlaan (1), and Taurog, Chaikoff and Feller (2) have shown in the rat that, even after hormonal synthesis has been blocked by an antithyroid drug such as propylthiouracil,