INTENSITY OF LIPID AND PROTEIN PEROXIDATION PROCESSES IN THE DYNAMICS OF IMMOBILIZATION STRESS ON THE BACKGROUND OF HYPOTHYROSIS

Abstract

Introduction. Stress is a reflection of all the adaptive reactions of the body, non-specific biological phenomena that occur in response to various stimuli and aimed at the implementation of adaptive mechanisms that adapt the body to stress effects [5]. An important role in the implementation of adaptive reactions of the body play the hormones of the thyroid gland, which are able to mobilize the body's reserves to repair the damages caused by the action of the stress factor. The thyroid axis is naturally involved in the processes of adaptation of the organism to the action of extreme stimuli. However, the changes in the thyroid gland function under stress and adaptation do not allow us to estimate the value of thyroid hormones in adaptive responses. A comprehensive study of the hormonal spectrum and the state of redox processes in the body of experimental animals with altered thyroid status under conditions of additional stressful effects of various nature is necessary.

The aim of the study – to learn the intensity of lipid and protein peroxidation processes under immobilization stress in rats with experimental hypothyroidism.

Research Methods. Hypothyroidism was simulated by daily per os injection of mercazolilum thyreostatics (“Health”, Ukraine) at a dose of 25 mg/kg for 21 days. Acute immobilization stress was simulated by tying experimental rats in a supine position by 4 limbs without limiting the mobility of the head for 3 hours. Spectrophotometric and enzyme immunoassay methods were used to study the concentration of iodine-containing thyroid hormones and the activity of lipid and protein peroxidation processes.

Results and Discussion. It was established that under conditions of deficiency of iodine-containing thyroid hormones, the activity of free radical oxidation of lipids and proteins was significantly lower than in animals without simulated pathology. In the study of the effect of immobilization stress on lipid and protein peroxidation indicators, it was established that at the stage of anxiety of the development of a stress reaction in euthyroid animals, the indicators of lipid and protein peroxidation increase, which indicates an increase in the activity of the free radical processes. At the stage of resistance, stabilization of the activity of free radical processes occurs. However, during prolonged stress (exhaustion stage), the activity of free radical processes increases significantly, which indicates the depletion of the protective reserve of the antioxidant system. In animals with hypothyroidism, there is a gradual significant increase in the intensity of lipid and protein peroxidation processes at all stages of the development of a stress reaction with a maximum at the stage of depletion.

Conclusion. In the setting of hypothyroidism, there is more intense than in euthyroid animals, increase in the intensity of protein and lipid peroxidation processes at all stages of the development of stress response.