FEATURES OF CHANGES OF ANTIOXIDANT SYSTEM IN DYNAMICS OF IMMOBILIZATIONAL STRESS ON THE BACKGROUND OF HYPOTHYROIDISM

Abstract

In the pathogenesis of many pathological conditions, an important place is occupied by violations of the antioxidant system. In the absence of proper control over the activity of free radical oxidation processes, a number of pathological conditions develop, accompanied by the occurrence of destructive, inflammatory and immune reactions. A number of researchers have established the protective effect of iodine-containing thyroid hormones during stress, which is realized as a result of their interaction with the cellular genome, which leads to the stimulation of local stress-limiting systems.

The aim of the study – to establish the features of the functioning of the antioxidant system in conditions of immobilization stress against the background of a decrease in the level of iodine-containing thyroid hormones.

Materials and Methods. Hypothyroidism was modeled by daily per os injection of mercazole thyreostatics (Health, Ukraine) at a dose of 25 mg / kg for 21 days. Acute immobilization stress was modeled by tying experimental rats in a supine position in 4 limbs without limiting the mobility of the head for 3 hours. To study the concentration of iodine-containing thyroid hormones, enzyme immunoassay methods were used, and indicators of the antioxidant system were spectrophotometric methods.

Results and Discussion. The effect of immobilization stress in rats with pre-modeled hypothyroidism on the indicators of the antioxidant system of the blood was studied. At the stage of anxiety of the development of a stress reaction in euthyroids, insignificant inhibition of antioxidant protection was observed, manifested by a decrease in the activity of the main antioxidants of the first line – catalase and superoxide dismutase, a decrease in the concentration of ceruloplasmin and inhibition of the glutathione link of the antioxidant system. At the stage of resistance, stabilization occurs, and in some cases an increase in the performance of the antioxidant system relative to animals without pathology. However, with prolonged stress (exhaustion stage), the antioxidant potential of the blood again decreases significantly, which indicates the depletion of the protective antioxidant reserve. In animals with hypothyroidism at all stages of the development of the stress reaction, there is a significant suppression of the antioxidant ability of the blood in both animals without modeled pathology and euthyroid animals with immobilization stress.

Conclusion. Against hypothyroidism, there is more intense inhibition of antioxidant ability of blood than in euthyroid animals.