EN
INTRODUCTION: Over the last few decades, electromagnetic pollution from generated electromagnetic fields increases. Particularly important from the point of view of our health is the exposure to extremely low frequency electromagnetic fields (ELF‑EMF). ELF‑EMF is derived from many man-made sources, including power transmission lines or transformers. The effects induced by ELF-EMF exposure on biological systems are still unclear. AIM(S): Therefore, the aim of this study was to determine the long‑term consequences of 50 Hz ELF‑EMF of 1mT and 7mT on the noradrenaline level stress parameter in the rat brain. METHOD(S): 3-month-old male Wistar rats were divided into groups: 1) sham animals (directly taken from home cage; non‑treated), or 2) animals exposed to ELF‑MF (50 Hz, induction 1 mT or 7 mT). Animals were exposed to low (1 mT) or high density (7 mT) ELF‑EMF for one week, for 8h/day. Control animals were subjected to the same experimental procedure as the respective animals exposed to ELF-EMF except magnetic field exposure. The level of noradrenaline in the hypothalamus was measured using HPLC immediately and 5 weeks after the exposure in the group exposed to 1mT and in the group subjected to 7mT, additionally 9 and 13 weeks after the exposure. RESULTS: The results have shown that ELF-MF of both inductions (50 Hz) increased the level of noradrenaline in rats immediately after the exposure and the change in this hormone level was clear even 3 months later, but only in rats exposed to 7mT. CONCLUSIONS: In conclusion, our data indicated that ELF-MF changes noradrenaline levels in the rat brain. Changes found in the present study suggest that extremely low frequency electromagnetic fields could be considered as a stress factor and can be a cause of the development of stress‑related disorders. FINANCIAL SUPPORT: Research supported by project no. 2017/25/B/NZ7/00638 National Science Centre, Poland.