Influence of Mild and Severe Cellular Dehydration on Histochemical Changes in the Thyroid Parenchyma of Rats

Ukrainian and foreign authors pay extra attention to the examination of thyroid gland diseases and summarize their observations in numerous studies and clinical articles. However, the progress achieved in diagnosis and treatment cannot solve the problem completely. The results cannot be considered satisfactory due to the high morbidity and development of severe complications. The main factors that lead to different pathology of the thyroid gland are: iodine deficiency or, at least its toxicity, radiation influence, toxins, other negative environmental factors, genetic factor, autoimmune processes, Hypothalamus-pituitary area dysfunction, surgical and medicated factors, etc. Thyroid gland plays an important role in normal functioning of the human organism. Exactly thyroid gland among the endocrine glands appears to be the first in the process of embryogenesis. Thyroid gland, which has relatively «simple» basic structure, depending on the activity level and period of the ontogeny, shows various forms of morphological organization, functional interpretation of which is not always definitive. That is why, thyroid gland research attracts scientific interest and this particular organ is the object of our research. The main aim of our experiment is to examine thyroid gland tissue of rats with the help of histochemical method in conditions of light and severe Cellular dehydration. These particular animals were chosen for our experiment, because the structure and functional condition of rat's and human's thyroid glands have significant similarity. For the histochemical study during the collection of biomaterials the right share of the thyroid gland was separated. Collected tissue was fixed in 10% solution of neutral formalin solution during 24 hours. After fixation the specimens had been washed under the flowing water during an hour. Construction and production of the paraffin blocks were carried out using the generally accepted method. Further, on the microtome MS-2 there were made series of paraffin cuttings with a thickness of 8-10 microns. Subcapsular and intermediate areas of thyroid were colored with haematoxylin-eosin. Received histochemical specimens were pictured and examined with the digital morphometric complex. As result of the study it was found out that under conditions of light and severe cellular dehydration there is a slight disorder in the structure of the follicular apparatus, the amount of stroma increases, as well as the amount of degenerative structures in the glandular parenchyma, thus morphofunctional activity of thyroid increased slightly, especially since the beginning of the experiment. The preservation of the division of organ tissues into central and peripheral parts is present. Proliferous activity did increase. The histoarchitecture disorder occurs in conditions of cellular dehydration of severe degree, because the significant part of the follicles has morphological signs of hypofunctional condition, also there is a distinct swelling of all histological structures and sclerotization of the stroma of the gland. Discirculatory disorder of the thyroid tissue is at the forefront: severe edema of both the stromal and the cellular component, marked by vascular congestion and small hemorrhaging.