Abstract:
Very frequent natural and man-made disasters as well as current military conflicts are
accompanied by injuries complicated by acute blood loss, burns and shock of different
degrees of severity. Thermal injuries are one of the world modern medicine most urgent
medical and social problems including the same in Ukraine. In response to a burn injury
a significant number of pathological processes develop in the body which manifestation
involves almost all organs and systems, leading to an expressed homeostasis disturbance
and adaptative processes disorder. Thyroid gland is the one of the first which receives
the alterative influence in conditions of both threshold and suprathreshold thermal
exposure. The purpose of the work is to establish histological and ultrastructural changes
in the thyroid gland of experimental animals 30 days after thermal skin injury. Experimental
studies were conducted on 90 white male rats. Skin thermal burns were simulated using
four copper plates application to previously depilated lateral surfaces of the rats' body for
10 s. Rats were injected with a 0.9 % saline into the vena cava inferior during the first 7 days
of the post-burn period. Thyroid gland pieces were fixed in a 10 % neutral formalin solution,
dehydrated in alcohols of increasing concentration and embedded in paraffin blocks. The
prepared sections of 5-6 μm thickness were stained with hematoxylin-eosin. In the rats'
thyroid gland the presence of complex changes of a destructive, adaptive-compensatory
and regenerative nature was established on the 30th day after a skin burn against the
background of 0.9 % NaCl administration. These changes indicate a relative organs
hemodynamics normalization together with the structure of various diameters vessels
walls which creates the basis for the follicular cells typical structure restoration and new
follicles synthesis. The expressed osmiophily and thyrocyte nuclei pyknotization, cytoplasm
vacuolization and follicle's lumen cells desquamation are revealed in the gland parenchyma.
These are signs of the organ fibrosis which are supported by connective tissue amount in
the stromal component increase. The thyroid gland parenchyma and the vessels surrounding
it micro- and ultrastructural changes caused by the thermal altering influence have a timedependent expression which transforms from predominantly destructive to predominantly
restorative throughout the 30-day post-burn period. The authors are sure that the detected
morphological changes of the gland have a time-dependent reversibility which is important
to consider from both the time-course and the quantitative aspects taking into account the
pathogenetically based scheme of pharmacocorrection. The 30th day of the post-burn
pathological process manifestation characterizes by a certain imbalance in the
compensatory, restorative and synthetic processes manifestation as well as in the
destructive and decompensatory processes manifestation which gives reason to hope
for the thyroid gland functioning restoration together with organs and systems in case of
pathogenetically determined pharmacological treatment administration. Taking into
account the thyroid gland morpho-functional changes wave-like dynamics the authors
believe that sanogenetic mechanisms activation might occurs which will allow to prescribe
the complex pathogenetically determined correction assuming the above-mentioned
patho- and sanogenetic mechanisms dynamics.
