The microscopic and ultramicroscopic changes of the white rats’ thyroid gland 7 days after experimantal thermal burn injury under nacl systemic adminastration

Abstract

The conducted microscopic and ultramicroscopic examinations revealed that 7 days after experimental burn injury the thyroid gland exhibits alterations of the follicular structure, thyroid epithelium, blood vessels and stroma. Most of such alterations are the signs of thyroid destruction. In the central regions of the lobules there are small follicles containing small amount of colloid; the latter is rarefied, fine, slightly oxyphilic and contains large resorption vacuoles. The cells of the thyroid epithelium are columnar or cuboidal; their characteristic features are intracellular edema, hypochromic nuclei and irregular cell borders. The stromal interfollicular connective tissue is swollen, containing leukocyte infiltrates, mainly in its perivascular regions. Both thyroid arteries and veins are blood-filled, and their walls are swollen. he tunica media of the arteries is enlarged; its smooth muscle cells exhibit intracellular edema and contain intensely basophilic nuclei. Impaired thyroid hemodynamics is also manifested by the changes in the vessels of the microvascular bed: most venules are bloodfilled, the walls of arterioles are thickened and swollen, containing perivascular leukocyte infiltrates. All human studies were conducted in compliance with the rules of the Helsinki Declaration of the World Medical Association "Ethical principles of medical research with human participation as an object of study". Informed consent was obtained from all participants.