Morphological and Histological Study on Thyroid Gland Toxicity in Male Rats Exposed to Mercury

The present study investigated the effect of heavy metals (Mercury chloride) on the morphological andhistological feature of the thyroid gland. Rattus norvegicus male rats were selected for experimental use.the rats given doses of Hg salts (3mg/kg, Ip.3times weekly for 4 week) admin is tration alteredthe body weight, thyroid weight, length and width of thyroid gland. Morphologically, the thyroid glandwas consisted of two labs of reddish brown in color, the lobes were located on ventral Lateral side oftrachea connected caudally with isthmus. While the thyroid gland treated rats recorded changes in color(pale), swollen and enlarged. histologically, the architectural cellular structure gland of the thyroid glandof exposed rats recorded variations in the follicular thyroid, congested blood vessels and depletion of parafollicular cells in the rats treated to Hg in a comparison to that of the control rats. This signify that animalsexposed to Hg could at a risk of thyroid gland.