Inhibition of Thyroid function by cortisone and ACTH in Hypophysectomized Rats.

Abstract
Administration of cortisone or ACTH decreases the TSH-induced uptake of I131 by the thyroid of hypophysectomized rats. This indicates that the suppression of the iodine concentrating function of the thyroid is brought about at extrapituitary levels, and not by suppression of TSH secretion from the pituitary.