Effect of enhanced bromide intake on the concentration ratio I/Br in the rat thyroid gland.

Interaction of bromine with iodine was studied in the rat thyroid gland under the conditions of different bromide intake. Bromine and iodine in the thyroid dry weight were determined by instrumental neutron activation analysis (INAA). It was found that with increased bromide intake the bromine concentration in the thyroid gland increased with simultaneous decrease in the iodine concentration. The change in the I/Br concentration ratio depends on a number of halogen binding positions and on the bromide supply. The I/Br parameter reacts sensitively to the changes of bromide intake already in the region of low bromine concentration levels.