Experimental Models of the Hypothyroidism

Abstract

Hypothyroidism is a systemic chronic disease that occurs as a result of a deficiency of thyroid hormones (thyroid hormones): triiodothyronine and tetraiodothyronine (thyroxine). Targets of thyroid hormones are almost all organs and tissues of the human body, which explains the variety of clinical manifestations that occur when these hormones are deficient. Recently, basic research through the use of experimental models has become more relevant and allowed us to obtain a number of new morphological and functional changes that occur in hypothyroidism. This review discusses the main experimental models of hypothyroidism: surgical, radioactive, dietary, anti-thyroid administration and genetics’ model. The main principle of the surgical model of hypothyroidism is to remove the thyroid gland. The radioactive model is based on the introduction of a radioactive isotope of iodine to laboratory animals. The dietary model is based on the use of a special diet with a limited amount of iodine. The drug model is based on the introduction of antithyroid drugs - methylimidazole and propylthiouracil. The principle of the genetic model consists in special genetic manipulations with the genome of laboratory animals. The advantages and disadvantages of each model are discussed. The use of sophisticated equipment has brought specialists closer to a more complete and holistic understanding of the morphological and functional manifestations of hypothyroidism. Researching of experimental models is an important tool in relation to the studying of the mechanisms underlying hypothyroidism and, as a result, in improving prevention and treatment-diagnostic strategies.

Histopathological Changes in the Nucleus and Contractile Apparatus of Cardiomyocytes in Overt Acquired Primary Hypothyroidism: Experimental Study

“…The most common forms of hypothyroidism in actual clinical practice are primary acquired hypothyroidism of clinical and subclinical degrees of severity [1][2][3]. Recently, morphological studies of histopathological changes in organs and tissues of mammals under induced hypothyroidism have become highly relevant in fundamental medicine [6][7][8][9]. According to a number of morphological studies, hypothyroidism causes significant structural changes in the organs and tissues of the cardiovascular system [7][8][9][10][11][12][13][14], the skin and its derivatives [15,16], the musculoskeletal system [17,18], and the reproductive system [19,20].…”

“…Recently, morphological studies of histopathological changes in organs and tissues of mammals under induced hypothyroidism have become highly relevant in fundamental medicine [6][7][8][9]. According to a number of morphological studies, hypothyroidism causes significant structural changes in the organs and tissues of the cardiovascular system [7][8][9][10][11][12][13][14], the skin and its derivatives [15,16], the musculoskeletal system [17,18], and the reproductive system [19,20]. To date, a number of morphological studies of the myocardium at the tissue level of organization have been carried out.…”