The interference of excessive bromide intake with iodine metabolism in the rat was studied using 82Br and 131I radionuclides. Mainly lactating rat dams and their pups were used, in addition to adult male rats, in the present studies.
Particularly, the influence of high bromide intake in lactating rat dams on the transfer of iodine and bromide to suckling
young through breast milk was evaluated. The induction of hypothyroid status in the pups by high bromide intake in the mothers
was proved unambiguously. Excessive bromide in lactating rat dams caused a marked decrease in plasma levels of thyroid hormones
both, in the mothers and in their sucklings. The effects of an enhanced bromide intake on the thyroid function in relation
to iodine status in the animals were also followed. Marked goitrogenic and thyrotoxic effects of excessive bromide in adult
rats were significantly enhanced under the conditions of simultaneous iodine deficiency in the experimental animals.