Influence of Dietary Iodine on I 131 Retention and Distribution in the Chick. ∗

Abstract

Summary

Chicks fed an iodine deficient ration retained more I¹⁸¹ originally than did control chicks. The more rapid loss of I¹³¹ from the deficient chicks, however, was such that the I¹³¹ concentration in the deficient chicks was significantly lower than that in the normal chicks by the end of the experiment. Studies of the distribution within the body revealed that the thyroids of deficient chicks trapped a maximum of 41% of the injected dose at 2 hours and had a biological half-life of the thyroidal I¹³¹ of approximately 15 hours. Control chicks, while trapping a maximum of only 4.5% of the injected dose at 8 hours, exhibited a biological half-life of more than 96 hours. A possible explanation for the rapid disappearance of injected I131 in the deficient chicks is discussed.