The present study aimed to evaluate the effects of isothermal non-ionizing electromag-netic field (EMF), represented by the man-made visible light, on the reproductive capacity of mice. Male mice were exposed to artificial visible light (intensity of 77 mW/cm2 on the area of 72.5 cm2 and frequency of EM radiation between 3.9 x1014 Hz and 7.5 x1014 Hz W/cm2) eight hours/day for 5, 7, and 15 days. The present results indicated that exposure of male mice to visible light for five or seven days showed dramatic alterations in the histological architecture of the testis, moreover, exposure for 15 days induced a complete degeneration of germ and Sertoli cells. Gonadotropic hormones levels; FSH and LH were signify-cantly declined by Day 5 and were not detected absolutely at days 7 and 15. In general, immunoreactivity of spermatogonia to proliferating cell nuclear antigen (PCNA) decreased in exposed mice. Moreover, germ cell apoptosis assessed by in situ terminal transferase-mediated end labelling (TUNEL) increased significantly in 5 days exposed mice and highly increased in 7 days exposed mice compared with controls. Bcl-2 protein decreased and Bax protein increased after exposure. Additionally, tumour necrosis factor-alpha (TNF-α) protein content decreased significantly in germ cells after exposure. The present investigation indicated that there is a strong coincidence between the effects of man-made EMF on gonadotropic hormone level expressions and the occurrence of apoptosis in the testis. These data suggest that the man-made EMF interferes with stages of spermato-genesis by disruption of pituitary gland function. In conclusion, man-made visible light radiation affects negatively on the reproductive capacity of male mice.
Key words: Electromagnetic field, testis, gonadotropic hormones, apoptosis, mice