I131 metabolism in thyroid slices of patients with various thyroidal disorders.

Abstract

Slices of thyroid tissue, obtained at operation from euthyroid patients and from patients with Graves' disease, adenoma, carcinoma and several types of thyroiditis were studied in a gravity-flow system of incubation in a medium of constant composition containing I131. The metabolism of I131 was expressed in terms of the clearance of I131 by the slice, tissue-medium (T/M) gradients, ability to bind iodine in organic form, and ability to discharge accumulated radioiodine in response to thiocyanate both in the unblocked state and afterocking with methimazole. Slices of normal thyroid tissue had similar clearance values (0.03 ml./min./Gm.) and T/M ratios (3 to 4) whether organic binding was permitted or abolished. Only half of the accumulated I131 was protein-bound when binding was allowed, and the remaining I131 was dischargeable by thiocyanate. When Lugol's solution had been administered preoperatively, the above values were reduced to 50 and 75 per cent. The clearance by slices of exophthalmic goiters was ...