The obesity problem requires a study of its pathophysiological consequences affecting hormonal regulation and organism’s reactivity to extreme exposures. The study was aimed first to examine the effect of a high-calorie diet and social isolation, as well as their combination for 4 months, on the development of obesity, its metabolic and behavioral sequelae, features of the thyroid status, while at the second stage, to assess the reaction of hormonal indices of the thyroid status to short-term stress in rats. The experiments were carried out on male Wistar rats and at the first stage focused on the effects of a high-calorie diet and social isolation, as well as their combinations for 4 months. At the end of the experiment, behavioral reactions, metabolic syndrome indices, thyroid status, and cortisol levels were evaluated. At the second stage, the animals were exposed to short-term acute stress, and the shifts in the hormonal indices were recorded one hour later versus the initial background. A high-calorie diet led to the development of metabolic syndrome, signs of depression, increased thyroid-stimulating hormone (TSH), thyroxine and triiodothyronine serum levels, as well as iodothyronine deiodinase type 1 (D1) activity, in the rat liver. At the same time, there was a decrease in thyroperoxidase activity and an increase in thyroid levels of triglycerides and malondialdehyde. The physiological response to stress in the control rat group included an increase in cortisol and TSH serum levels, however, against the background of a high-calorie diet, no cortisol release into the bloodstream was recorded. Social isolation did not alter normal reactivity of the adrenal cortex, but reduced TSH release in response to acute stress, since the initial level of this hormone was slightly elevated against the background of chronic social isolation stress. Thus, excessive nutrition and the deficit of social activities in male Wistar rats led to significant changes in the organism’s reactivity to acute stress.

No abstract

Obesity causes a wide range of pathophysiological consequences in the body, affecting the sphere of hormonal and psycho-emotional regulation. The aim of the study is to investigate the effect of a high-calorie diet on the development of obesity, reproductive status hormone levels and behavioral features of male Wistar rats, as well as the possibility of normalizing the identified shifts with non-medicinal options for obesity correction. Experiments were performed on 80 sexually mature male Wistar rats for 16 weeks and included 6 groups of animals, taking into account the diet (standard vivarium diet, highcalorie diet and transition from a high-calorie diet to a standard diet at the 2nd stage of the experiment) with or without the moderate physical activity in the form of treadmill running at the 2nd stage – the last 8 weeks of the experiment. A longterm high-caloric diet (16 weeks) caused visceral obesity, elevated glucose, cholesterol and triglyceride levels, dramatically decreased serum testosterone and estradiol levels, and depression manifestations in the Porsolt test in male Wistar rats. Successful correction of obesity, metabolic shifts and depressive behavior in rats was achieved by switching to a balanced diet during the last 8 weeks of the experiment. Normalization of testosterone and estradiol levels against the background of an increased serum luteinizing hormone level occurred in rats receiving a high-calorie diet (16 weeks) with the connection of physical exercise during the last 8 weeks of the experiment. Complex correction of obesity, which included the transition to a standard diet and exercise during the last 8 weeks of the experiment, led to a dramatic 2-fold increase in testosterone levels compared to control and a hyperactive phenotype in male Wistar rats. There is a close relationship between the depression development and testosterone levels in obesity and its correction.

A comparative analysis of structural organization changes in skin microcirculatory vessels, serum level of leptin, diponectin, resistin in the ase of metabolic syndrome and doxorubicin intoxication was performed. It was shown that hypertrophy of the muscle fibers, perivascular space edema, and skin arteriole spasm in the metabolic syndrome accompanied by a structural reorganization of the organs and their vessels by the type of dystrophy. In the case of doxorubicin intoxication, the alteration processes were dominant. Changes in the level of hormones leptin adiponectin and resistin in the metabolic syndrome and doxorubicin intoxication were multidirectional.

A literature review about the role of microrna in biological processes associated with .obesity was completed. Modern ideas about micrornas, their biogenesis and their role in the formation of adipose tissue, glucose and lipid metabolism were described. The possibilities of using microRNA as new biomarkers and therapeutic targets for development of anti-obesity drugs were considered.