EN
The aim of this study was the evaluation of the influence of extremely low-frequency magnetic fields (ELF-MF) on the morphology of thyroid epithelial cells in female rats. The rats were exposed to ELF–MF (frequency: 5-10 Hz, induction 10 mT), 1 hour daily for 7 days over a week for 4 months. Control animals were sham exposed. After that time the rats were sacrificed by anaesthetizing with Ketamine and decapitated. The animals’ thyroid glands were extracted. They served as microscopic preparations. In the preparations, the thyreocytes, nuclei, nucleoli and nucleo-cytoplasmatic ratio were evaluated. We concluded that changes in the location of nuclei, surface field, the number and surface of nucleoli and nucloli organizers show an increase in reply activity in the nuclei of thyreocytes and a probable increase of DNA synthesis.