EFFECT OF DIETHYLSTILBESTROL ON THE BINDING OF THYROXINE IN SERUM*†

Abstract

The occurrence during normal pregnancy of an augmentation of thyroxine -binding by the specific thyroxine-binding protein (TBP) of plasma, was confirmed. Diethylstilbestrol, when given to patients with a variety of endocrinopathies in a dosage of 30 mg daily for periods of 4 to 8 weeks, induced alterations in thyroxine-binding by TBP comparable to those which occur during pregnancy. This effect of diethylstilbestrol is not dependent on normal functioning of the thyropituitary axis, since it was noted in patients with hypopituitarism and with treated primary myxedema. Other effects of diethylstilbestrol on thyroidal economy were described, and their possible relation to altered thyroxine-binding by TBP was discussed.