Antithyroid Action in Rats of Small Doses of Some Naturally Occurring Compounds

Thiocyanate, goitrin and allylisothiocyanate were administered orally, either individually or in various combinations, by force-feeding to rats for a period of 21 days. Thyroid weight, 4-hr 13lI uptake, and synthesis of iodoamino acids were compared in each group to that in controls force-fed only distilled water. The quantity of the various substances tested administered daily was approximately equal to that calculated to be present in the amount of cabbage which the rats would consume daily. Combinations of the 3 test materials produced a greater alteration in thyroid function and increase in thyroid size than did administration of any one of them individually. It is concluded that the goitrogenicity of cabbage and other cruciferous plants may be explained by the combined action of the thiocyanate, goitrin and isothiocyanates contained therein. (Endocrinology79: 1117, 1966)