Histological Study of Thyroid Gland after Experimental Exposure to Low Frequency Electromagnetic Fields in Adult Male Albino Rat and Possible Protective Role of Vitamin E

Abstract

Introduction: Thyroid gland is one of the most important endocrine organs and almost all cells of the body are target sites for its hormones. Electromagnetic field became progressively more common constituent of the general and workplace environments. Aim of work: To evaluate the effect of low frequency electromagnetic fields (LF-EMF) on the structure and function of the thyroid gland and to evaluate their reversibility and role of vitamin E. Materials and Methods: Forty five adult male albino rats were equally divided into four groups; group I (control group), group II: rats were exposed to 50 Hz EMF for 1 month, group III: rats were received vitamin E just before EMF exposure for the same period and group IV (recovery group). At the time of sacrifice, blood samples were collected to estimate TSH, T3 and T4 levels. Thyroid gland specimens were processed for microscopic examination. The heights of follicular epithelium, collagen fiber area % were morphometrically estimated and statistically analyzed. Results: Exposed group showed significant decline T3 and T4 levels together with significant increase in TSH level as compared to other groups. Histologically, this group showed congestion and dilatation of blood capillaries, cellular infiltration, follicular disintegration and vacuolar degeneration of some follicular cells. Other apoptotic follicular cells appeared with condensed chromatin or desquamated. The epithelial height and connective tissue area also affected. Vitamin E improves the biochemical and histological picture of thyroid gland (group III). Recovery group (IV) had variable alteration as compared to other groups. Conclusion: LF-EMF has very serious effect on thyroid gland and vitamin E could have a protective role against this tissue damage.