Background: Thyroid gland has crucial importance for the normal function of different body organs and its hormones affect all body metabolisms. Electromagnetic fields are now widely used in various fields due to the great development and rapid expansion of technology. The aim of the present work was to investigate the histological, immunohistochemical and biochemical changes of thyroid gland after exposure to low frequency electromagnetic fields and the possible protective effect of vitamin C. Material & methods: Thirty adult male albino rats were classified randomly into four experimental groups. Group I: Control group that was fed on standard diet. Group II: rats were exposed to low frequency electromagnetic field for 1 month. Group III: rats were given vitamin C just before being exposed to electromagnetic field. Group IV: rats were kept as a recovery group for 1 month following electromagnetic field exposure for the same period. At the end of experimental period, all of the rats were scarified. TSH, Free-T3 and Free-T4 were assessed. Thyroid sections were subjected to H & E, massontrichrome and caspase 3 immunohistochemical stains. Morphometric and statistical studies were analyzed. Results: In electromagnetic field exposed group, there were significant increase of TSH with significance decrease of free T3 and free T4 in comparison to control group. Within this group, there were several pathological changes including: distorted walls, displacement of desquamated epithelial cells in their lumens, cytoplasmic vacuoles, deeply stained nuclei, degeneration of follicles with exfoliated follicular cells in their lumens, congestion of blood capillaries, mononuclear cellular infiltration and strong positive caspase-3 reaction. Additionally, there were a significant decrease in the mean height of the follicular epithelium and significant increase in the mean area percentage of collagen fiber content compared to the control group. There was apparent improvement with the use of vitamin C during period of exposure. Conclusion: Our results demonstrate the deleterious changes of thyroid gland morphology and activity due to electromagnetic exposure. Vitamin C is considered to have protective effect against these changes. [ |
