Morphofunctional Changes in the Thyroid Gland of Sexually Mature Male Rats in Acetic Acid Poisoning

Acetic acid poisoning is not only accompanied by a pronounced tropic action of the poison, but also has a non-specific effect due to a toxic stress reaction. The specific effect of this toxicant on various internal organs has been studied in sufficient detail. In response to the action of the stressor, stress hormones are released not only by the adrenal glands, but also by the thyroid gland. However, the role of the thyroid gland and the degree of involvement of thyroid hormones in the response to poisoning have not been investigated. The purpose of this article was to study the nature of morphological changes in the thyroid gland in a model of acute acetic acid poisoning and to determine the dynamics of thyroxine levels. Materials and methods. The experiment involved 30 sexually mature male mongrel rats with an initial weight of 160–180 g, who were divided into experimental (n = 25) and intact (n = 5) animals. A model of acute acetic acid poisoning was used. The experimental group was exposed to a 30 % solution of acetic acid, which was administered endogastrically in a single dose of 0.5 ml. Thyroxine levels were determined by enzyme immunoassay using special test kits. Samples were taken on the 1st, 3rd, 5th, 7th and 10th days after the administration. The thyroid gland was fixed in 10 % neutral formalin for histological examination. Results. Acute acetic acid poisoning impairs thyroxine production and causes changes in the thyroid gland structure. Morphological changes occur both in the gland’s stroma and in the parenchyma. Marked restructuring is noted on the 7th day after poisoning. This is manifested by hyperplasia of the thyroid tissue as well as by accumulation of colloid and an increase in its density. At the same time, dystrophy of the stroma and signs of sclerosis develop in the gland.