Effect of Large Doses of Iodide on the Peripheral Metabolism of Thyroxine in Rats

Abstract
The effect of large doses of iodide on the peripheral metabolism of thyroxine (T4) has been evaluated in studies conducted in rats in which the peripheral T4 pool was brought to specific activity equilibrium by daily injections of 131I-labeled T4 together with stable hormone. Doses of iodide as high as 5.0 mg daily failed to influence either the gastrointestinal or deiodinative routes of T4 metabolism.