Long-term action of potassium bromide on the rat thyroid gland

Acta Histochem. 1998 Feb;100(1):11-23. doi: 10.1016/S0065-1281(98)80003-2.


Male rats fed by a standard diet with determined of bromine and iodine content were exposed to a 133-day oral administration of KBr (100, 200, 400 mg Br-/l drinking water). Their thyroid glands showed increased growth of the epithelial cells reflected by a microfollicular rearrangement of the parenchyma due to proliferation of very small follicles with a low or zero content of colloid. Morphometric analysis of thyroids of Br(-)-exposed animals revealed a significant decrease in the volume of intrafollicular colloid and marked increase in the number of the smallest follicles (areas up to 100 and 100-300 micron 2). In addition, the nuclei of thyrocytes showed an increased number of mitoses. The vascularization was increased as well. In the blood plasma of the Br(-)-exposed animals the T4 concentration was significantly decreased in dependence on the bromine concentrations. Thyroglobulin immunoreactivity in the colloid of Br(-)-exposed animals decreased after administration of 400 mg Br-/l drinking water. Increasing concentrations of Br- in the drinking water caused an increased bromine concentration in the thyroid, a decreased iodine content and a decreased I/Br molar ratio. The changes in the rat thyroid caused by long-term administration of 100 mg Br-/l were similar to hyperplastic parenchymal goitre and were comparable to those induced in previous experiments by the same bromine concentration administered over a 16- and 66-day period respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Bromides / administration & dosage*
  • Drug Administration Schedule
  • Male
  • Potassium Compounds / administration & dosage*
  • Radioimmunoassay
  • Rats
  • Rats, Wistar
  • Thyroglobulin / chemistry
  • Thyroid Gland / chemistry
  • Thyroid Gland / drug effects*
  • Thyroid Gland / pathology*
  • Thyroid Gland / ultrastructure
  • Thyrotropin / blood
  • Thyroxine / blood
  • Triiodothyronine / blood


  • Bromides
  • Potassium Compounds
  • Triiodothyronine
  • Thyrotropin
  • Thyroglobulin
  • potassium bromide
  • Thyroxine