Localization of protein-bound radioactive iodine in rat thyroid glands labelled with 125I or 131I

Abstract
Radioautographic studies of rat thyroid glands have been made at different times after labelling with I125 and I131 . Cellular organic radioiodine has been demonstrated in the thyroid of an untreated rat after 2 hr. labelling with I125. Cellular organic radioiodine has been demonstrated in thyroids of rats pretreated with iodide, and labelled with I131 for 10 and 15 min.