Morphological and morphometric features of fat tissue in rats with the development of chronic inflammation against the background of the metabolic syndrome

Background. Obesity in rodents is considered as an increase in body weight due to fat depots when they are given a high-fat diet, which contributes to an increase in the internal body weight. Modeling of metabolic syndrome (MS) was carried out on white female rats, aged 5–6 months, to determine morphological and morphometric changes in adipose tissue and to establish the relationship with the development of chronic inflammation. Purpose of the work is to study the morphological and morphometric features of adipose tissue in obesity in rats, to establish a relationship with markers of systemic inflammation, the level of leptin and pro-inflammatory cytokines in blood serum in metabolic syndrome. Materials and Methods. The research was conducted on 30 white female rats of the WAG / G Sto population, aged 5–6 months. For MC modeling, rats were divided into 2 groups: main (20 rats) and control (10 rats). Morphological and morphometric study of adipocytes was performed to quantitatively assess the state of adipose tissue. The concentration of cytokines and leptin in blood serum was determined by enzyme immunoassay. To confirm the development of MS in the animals of the main group, body weight, concentration of glucose, insulin, triglycerides, total blood cholesterol (ТBH), low- and high-density lipoproteins (LDL, HDL), and C-reactive protein (CRP) were evaluated. Results. Morphological and morphometric studies of adipose tissue confirm a change in the mass of adipose tissue due to the size of fat cells – hypertrophy of adipocytes. Metabolic markers of the metabolic syndrome are a specific adipokine – leptin, the concentration of which in blood serum characterizes the degree of its hormonal activity. It has been proven that an increase in leptin level in MS is not only a symptom that characterizes the functional state of adipose tissue, but also determines the spontaneous production of pro-inflammatory cytokines in the blood and is pathogenetically interconnected with the development of non-differentiated chronic inflammation. Conclusions. The morphological and morphometric study of the increase in the volume density of adipocytes, the size of their diameter and the number of infiltrates corresponds to the statement about inflammation of adipose tissue in the main group of rats. A change in the cytokine profile in the blood serum of rats can be not only a marker of the development of this type of adipose tissue inflammation, but also a prognostic sign of the effectiveness of the treatment of metabolic syndrome Key words: Metabolic syndrome, obesity, morphological and morphometric mechanisms, leptin, adipocytes, hypertrophic processes.