ROLE OF THE THYROID IN THE CYTOLOGIC RESPONSE OF THE PITUITARY TO LOW INTAKE OF IODINE11

THE rô1e of iodine in the physiology of the thyroid gland has been studied extensively, but the pituitary factor, which selectively alters the activity of the thyroid, presents new problems in the interpretation of the r61e of the pituitary as well as of the thyroid in the metabolism of iodine. The effect of iodine on the relation of the thyroid to the pituitary in the intact animal has been studied. Kuschinsky (1933) found that iodine administered in large doses apparently increased the thyrotropic content of the pituitary glands of animals as indicated by the response of the thyroid that the pituitary glands evoked when implanted into recipient animals. He concluded that iodine acts directly on the pituitary gland. Loeser and Thompson (1935) concluded that the pituitary is involved in the response of the thyroid to iodine, for they were unable to produce a cytologic change of the thyroid glands of hypophysectomized animals by the injection of amounts of iodine which gave a satisfactory response in intact animals.