Effect of Thiocyanate, Perchlorate and Other Anions on Thyroidal Iodine Metabolism

Abstract

Rat thyroid lobes were incubated with I131 - in graded concentrations of thiocyanate, perchlorate, nitrate, chlorate and fluoborate. All anions tested inhibited both concentration of inorganic iodide by the thyroid tissue and, in higher concentration, organic binding of that iodide which did enter the thyroid Both inhibitory phenomena could be reversed by leaching lobes preincubated in effective concentrations of any of these anions. Perchlorate was most effective in inhibiting iodide concentration, while thiocyanate was the most potent inhibitor of organic binding. High concentrations of perchlorate and thiocyanate, the only 2 anions so tested, also inhibited both iodide concentration and organic binding of iodine in vivo. The patterns of inhibition of the various functions indicated that there are qualitative as well as quantitative differences between the various anions, particularly between thiocyanate and the others.