Влияние ожирения на развитие инсулинорезистентности и окислительного стресса в эксперименте

Abstract

Purpose. To study influence of abdominal obesity on the formation of peripheral insulin resistance and development of oxidative stress in rats. Materials and methods. Diabetes was developed in 90 white male rats and nonporous females of the Wistar line weighing 80–120 g. In the first group of rats, diabetes mellitus was induced by a single intraperitoneal injection of a 2.5% solution of the antibiotic streptozotocin at a dose of 60 mg/kg of animal weight during a 24–48-hours fasting. In the second group, newborn rats were given a 2.5% solution of streptozotocin once at a dose of 60 mg/kg of body weight, while these rats received a diet enriched with lipids. The composition of the diet included: 8% protein, 30% fat, 62% carbohydrates. The control group received an equivalent amount of saline. The dynamics of carbohydrate and lipid metabolism was assessed. Results. In rats with type 2 diabetes mellitus (DM2) with abdominal obesity and DM2 without obesity structural and functional disorders developed in the membranes of erythrocytes and eye lens fibers, which correlate with indicators of glucose-insulin homeostasis and the level of lipid peroxidation. However, in rats with DM2 and abdominal obesity, the changes in the studied parameters were more significant. Conclusion. Streptozotocin-induced diabetes in obese rats, along with dyslipidemia, leads to the formation of insulin resistance, as evidenced by an increase in the degree of hyperglycemia, a decrease in the activity of insulin receptors and glucose uptake by cells against the background of the development of oxidative stress. The initiating factor of eye lens clouding in cataracts in rats with DM and obesity is apparently a shift in osmolarity in the cells of lens fiber membranes because of the accumulation of insoluble forms of sorbitol and fructose in them. Key words: diabetes mellitus; obesity; streptozotocin; antioxidants; insulin receptors; diabetic cataract; senile cataract