CHANGES OF THYROID GLAND STRUCTURES DURING CEREBRAL HYPOPERFUSION COMBINED WITH SHORT-TERM PHYSICAL EXERCISE
Sufficient thyroid activity is a prerequisite for mitigating the damaging effects of cerebral hypoperfusion. Thyroid status is also associated with sex and typological features, which can influence the effectiveness of physical activity as a part of rehabilitation measures. The research purpose is to assess the dynamics of structural changes in the follicular apparatus and hemomicrocirculatory channel of the thyroid gland during cerebral hypoperfusion in rats depending on sex and level of stress resistance under the influence of physical activity. Materials and methods. After bilateral ligation of the common carotid arteries, as well as when the operation was combined with physical exercise, morphometry of thyroid gland sections was performed, separately for males and females, animals with high (HSR) and low levels of stress resistance (LSR). The sections were studied on days 1, 6, 8, 14, 28, 35, 60 and 90 of the experiment. Results and its discussion. We revealed a periodicity of changes corresponding to the data obtained earlier for the adaptation of intact rats to 1.5 hours daily swimming. The lowest values of thyrocyte height during cerebral hypoperfusion averaged 6.6±0.7 μm (8 days): the minimum values were typical for LSR (6.1±0.3 μm) and females (6.5±0.3 μm), the maximum for males (6.7±0.3 μm) and HSR (7.3±0.3 μm). Thyrocyte height increases by day 35, averaging 10.3±2.7 μm. Physical exercise reduced thyrocyte height at all times except on days 28 and 35 of the experiment (9.9±2.4 μm and 2.4±3.9 μm, respectively). The growth of the average thyrocyte height is due to the increasing of the index in the male subgroup (18.1±0.2 μm) and HSR (13.2±0.2 μm). Conclusions. Fifteen - minute swimming during cerebral hypoperfusion reproduces the dynamics of thyroid effects observed during adaptation to 1.5 hours of free swimming in intact rats. Male sex and HSR, potentiate the effects of physical exercise in the simulation of cerebral hypoperfusion.