THE EFFECTS OF VARIOUS DOSES OF RADIOACTIVE IODINE ON THE FUNCTION AND STRUCTURE OF THE THYROID OF THE RAT

Abstract

THE purpose of this investigation was to study simultaneously the anatomical and the functional changes in the thyroid gland of growing rats following the administration of graded doses of radioactive iodine. The various aspects of the study embrace the following: 1. The initial uptake of a variety of doses of radioactive iodine by the thyroid, the rate of loss of the labeled activity from the thyroid, and the determination of the amount of radiation delivered to the thyroid. 2. The subsequent functional capacity of the irradiated thyroid gland as measured by its response to: a) A low iodine diet, b) Thiouracil, and c) Thyroid stimulating hormone (TSH) administration. 3. Growth of the animals as judged by the gain in weight and length of the body. 4. Histological changes associated with the above observations: damage, recovery, regeneration and possible tumor formation during prolonged periods of observation.