Korytskyi V. Morphofunctional changes of the thyroid gland after experimental thermal trauma and in combined use of lyophilized xenograft skin substrate

The dissertation presents a theoretical generalization and a new solution of the current scientific problem to establish the features of the thyroid gland structural components reorganization after experimental thermal trauma and its correction by lyophilized xenograft skin substrate. The experiments were conducted on 130 mature white male rats with the body weight of 180-200 g. The animals were divided into the following groups: 1st group – intact white rats; 2nd – animals with severe burns; 3rd – animals with thermal trauma, their wounds after early necrectomy of damaged skin were covered with a lyophilized xenograft skin substrate. The following research methods were used in the work: macroscopic – for visual establishment of the shape and topography of the thyroid gland; massometric – to quantify the absolute and relative mass of the body; injection – to determine the structural adjustment of the vascular bed of the thyroid gland; histological and electron microscopic – to establish qualitative changes in the structural components of the thyroid gland; morphometric – to obtain quantitative parameters of morphological components of the thyroid gland; enzyme-linked immunosorbent assay – to determine the content of hormones of the pituitary-thyroid system; biochemical – to determine the erythrocyte index of intoxication and the concentration of average molecular weight in blood plasma; statistical - to analyze the reliability of quantitative research results. For the first time with the use of a set of morphological methods of research the peculiarities of structural changes of the thyroid gland components of experimental animals after thermal trauma of the skin were studied. There were macroscopic, massometric, morphometric, micro- and submicroscopic changes established, which reveal the features of adaptive-compensatory, regenerative and destructive-degenerative changes of the organ under the conditions of experimental burn injury. It was found that the degree of morphological changes in the follicles, vessels, stroma and metabolic disorders of the thyroid gland of experimental animals differ in the dynamics of the experiment, and their nature and severity depend on the observation period. It is established that under the conditions of correction by use of xenograft skin substrate after early necrectomy of skin damaged by burns, the degree of destructive changes of follicular epithelium, vessels and interstitium decreases in early stages, and in the long run reparative processes are actively taking place and normalization of structural components of thyroid gland is perfomed.