Recently, there is a provoking interest for the effect of electromagnetic radiation on human health hazards. Therefore, this study was planned to evaluate the sub-chronic exposure effect of isothermal non-ionizing electromagnetic field (EMF) represented by the man-made visible light in vivo. Artificial visible light with intensity of 77 mW/cm2 on the area of 72.5 cm2 and frequency of EM radiation between 3.9 x 1014 Hz and 7.5 x 1014 Hz W/cm2 was subjected to 5-week old male CD1 mice 8 hours per day for 3, 6, and 12 days. Exposure caused variable degenerative effects on the histological architecture of the testes, reduction in the diameters of the seminiferous tubules besides a significant decrease in testes weights. Transmission electron microscope (TEM) examination of the testis showed that the degenerative effects were time-dependent in most germ, Sertoli and interstitial cells. DNA ploidy analysis on the testicular epithelium revealed significant time-dependent down-regulation of the proliferative activity in the germinal cells. In the pituitary glands, visible light caused also degenerative effects in the secretory cells particularly the gonadotrophs and mild to moderate hemorrhage after 3 and 6 days of treatment, and obvious hemorrhage and shrinkage of most secretory cells after 12 days of exposure. Serum biochemical analysis of testosterone, follicular stimulating hormone (FSH), luteinizing hormone (LH) and the hypothalamus gonadotropin releasing hormone (GnRH), were found time-dependently decreased particularly after 12 days. Visible light did not affect the serum total protein levels, albumin, albumin/globulin ratios, aspartate aminotransferase (AST) activity, alanine aminotransferase (ALT) activity or growth hormone (GH) levels. The results indicate that the man-made visible light may affect the endocrine homeostasis of mice by exerting histopathological changes in the pituitary gland and gonadotropic cells that may subsequently cause a harmful effect on the testis through reducing the gonadotropic hormones activities regulating the testicular integrity.
Key words: Visible light, Mice, Pituitary gland, Testis, TEM, Pathology, DNA ploidy, Gonadotropic hormones
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