Thyroidal Iodide Transport. VII. Acute Stimulation of Thyroidal Iodide Concentrating Ability by Cystamine and Cysteamine

Abstract

Administration of cysteamine or cystamine to rats leads to a 2- to 3-fold increase in the ability of the blocked thyroid to accumulate iodide ion. The effect occurs rapidly ( -5M) is unaffected by cystamine. Under special conditions, cystamine will stimulate the Na⁺+K+-requiring, ouabain-sensitive ATPase activity of the rat thyroid in similar time periods. The possibility that this enzymatic activity may mediate the effect of cysteamine and cystamine on iodide concentration is discussed. In addition, these compounds possess -l/50 the antithyroid activity of methylmercaptoimidazole. Cystamine is not goitrogenic, apparently because of the short duration of the antithyroid effect in vivo. This property appears not to be directly related to the augmentation of the T/S[I-]. (Endocrinology76: 949, 1965)