STUDIES ON THE THYROIDAL UPTAKE OF ASTATINE IN THE RAT*†

Abstract
Astatine has been found to be selectively concentrated by the rat thyroid gland. When the thyroidal uptake of astatine was compared with the thyroidal uptake of I131, more of the latter was taken up by the rat thyroid. When rats were treated with thiouracil, the thyroidal uptake of astatine was enhanced and only in thiouracil treated thyroid glands were clusters of alpha tracks found.