EFFECT OF THYROTROPIN ON CHANGES IN THYROID FUNCTION FOLLOWING ADMINISTRATION OF I131TO EUTHYROID CARDIAC PATIENTS*

Publisher Website
Google Scholar
Abstract
The thyroidal I131 uptake and turnover following multiple large doses of I131 were studied in 29 euthyroid cardiac patients with angina pectoris or congestive heart failure. The uptake of a 2d therapeutic dose of I131 administered 7 or more days after an initial therapeutic dose was markedly diminished; the turnover rate of the 2d dose was significantly more rapid. The effect of thyrotropic hormone (TSH) on thyroidal uptake and turnover following multiple therapeutic doses of I131 was studied in 8 patients with angina pectoris or congestive heart failure. In 7 of the 8 patients, admn. of TSH was associated with a reversal of the depressed I131 uptake and of the increased turnover usually observed after therapeutic doses of I131. In 3 instances the thyroidal uptake after TSH was 54-61%, within the range observed in thyrotoxicosis, in contrast to the expected 10-13%. TSH remained capable of stimulating I131 uptake when given as long as 54 days after the initial therapeutic dose of I131. It did not affect I131 uptake in a patient in whom myxedema had been induced 18 months previously.