The time course of iodine excretion in adult male rats substantially d
iffers from bromine excretion. Bromine is excreted at a single rate, w
hereas iodine evinces two excretion rates. Even a strong increase in b
romide intake in experimental animals failed to affect the rate of iod
ine excretion but it lowered the fraction of iodine accumulated in the
thyroid gland by 20% probably by affecting the transport of iodide in
to the thyroid gland.