[Functional state of the thyroid gland in rats receiving an increased quantity of iodine with drinking water].

Thyroid and adrenocortical function was examined in rats fed increasing quantities of iodine with drinking water. No noticeable deviations in thyroid hormone levels were found in the blood of experimental animals. Thyroid hormone levels in thyroid tissue were changing in the same direction in the animals kept on various iodine diets, these changes depending on experiment duration: an increase of thyroxine and more so, of triiodothyronine was observed in 50 days, and reduction thereof in 90 days. In rats fed the maximal iodine dose, 8000 micrograms daily, the level of thyroglobulin in thyroid tissue decreased. Increased iodine consumption reduced the glucocorticoid function of the adrenals in experimental animals, as manifested by reduction of corticosterone levels in the adrenals, blood plasma, and reduction of nonmetabolized hormone excretion with the urine.