Impaired organic binding of radioiodine by the thyroid following radioiodine treatment of hyperthyroidism.

Abstract

THERE have been several attempts to demonstrate a change in thyroid physiology following irradiation with radioiodine. Skanse (1) was able to show in chicks that the thyroid lost its ability to retain large doses of radioiodine and that its growth response to thiouracil and thyrotropic hormone was diminished following large doses of the isotope. On the other hand, Salter (2), using the thyroidal radioiodine uptake, serum protein-bound iodine concentration, and the rate of turnover of radioiodine into thyroxine, came to the conclusion that no appreciable change in thyroid function occurs in humans following therapeutic dosage with radioiodine. Evidence will be presented here of a specific change in thyroid function following such therapy. The work of McGinty and Sharp (3) in 1946 showed that radioactive iodine trapped by a thyroid gland which is under the effect of thiouracil remains in the inorganic form. Organic binding of the trapped iodide does not occur. This work was later confirmed by VanderLaan and...