міністерство освіти і науки, молоді - Медичний факультет ...

Харківський національний університет
імені В.Н. Каразіна
Медичний факультет
Актуальні питання сучасної медицини
CHANGES OF THE HYPOTALAMIC-PITUITARY-THYROID SYSTEM DUE TO
BURN INJURY
I.A. Bogdanov
Department of Pathophysiology
M. Gorky Donetsk National Medical University
Scientific adviser – M.D., Professor, G.K. Krivobok
Relevance of the topic. In recent years there has been an increasing trend in cases of burn
injuries in the industrial regions of Ukraine. Burn injury is one of the main reasons for the
increase of mortality and disability, and therefore is not only medical but also serious social
problem.
The aim of the study. The study of the functional state of hypothalamic-pituitary-thyroid
system (HPTS) in rats receiving burn an open flame.
Materials and methods. Was developed to model dose of thermal burns an opened flame in
the regulation of exposure, the flame temperature and area burned. The experiments were
performed on white male rats nonlinear weighing 200-250g in compliance with the norms and
principles of the European Convention for the Protection of Vertebrate Animals. Rats were
divided into two groups: one – intact, the second – the control, in which the simulated thermal
burn 5% of the body open flames (propane gas, the combustion temperature of approximately
1800 0 C) at a distance of 15 mm and an exposure time of 3s under ether anesthesia. Blood
was collected in a test tube to determine the concentration of thyrotropin (TSH),
triiodothyronine (T 3 ) and thyroxine (T 4 ), after which it was centrifuged. Determination of
hormone levels was performed using radioimmunoassay and ELISA methods.
Results. The level of hormones in plasma of rats from both groups (intact and control) was
investigated in an hour, day and three days after the burn. TSH (mIU / L): 0.407, 0.165 and
0.187, respectively, in intact rats - 0.148. The content of T 3 (pmol /L): 2.308, 1.605 and 3.070,
respectively; intact rats - 2.687. The content of T 4 (pmol / L): 87.32, 60.94 and 59.39,
respectively, in intact rats - 41.21.
Conclusions. Inhibition of TSH secretion is due to the fact that high concentrations of
circulating thyroid hormones reduce the sensitivity of receptors adenohypophyseal TSH-cells
to tireoliberin. This explains the drop in the level and points to the restoration of
neurosecretory process for the next day after the injury. Rapid elimination of tireoliberin from
the bloodstream after initiated by activation of the central link HPTS warns hyperactivation
thyroid system. Hyperactivation also prevents long-term increase in the concentration of T 4 in
blood plasma, which, according to the principle of feedback, inhibits the secretion of TSH in
the pituitary gland. Confirms the decrease in activity HPTS and the fact that the very next day
after the burn has been reduced conversion of T 4 to T 3 and tissue metabolism of thyroxine, as
evidenced by a significant decrease in the level of T 3 . On the third day after injury HPTS
indicators of activity were not significantly different from that of the intact group. It can be
concluded that the need for thyroid hormone and tissue metabolism in early postburns period
decreased due to the fact that in a post-traumatic hypoxia essential metabolic reaction is to
save intracellular energy, rather than a general enhancement of metabolism, which is just
driven by thyroid hormone. Thus, the central and peripheral units HPTS nonspecific, along
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