Intracellular Accumulation of Mercury in the Anterior Pituitary of Rats Exposed to Mercuric Chloride

A histochemical technique has been used to reveal mercury deposits by light and electron microscopy in the anterior pituitary of adult rats. After administration of mercuric chloride either in the drinking water or by intraperitoneal injection, deposits were found within lysosomes and secretory granules in somatotrophs, thyrotrophs, follicular cells, and marginal cells. The amount of mercury deposited was proportional to the dose of mercuric chloride given. Significantly more mercury was found in rats given intraperitoneal injections compared to those intoxicated with mercuric chloride in the drinking water. Mercury was retained in the cells for at least 4 months after the last injection although the amount of deposits decreased in this period.