Histomorphological Features of White Adipose Tissue in Rats of Different Ages With Visceral Obesity

Background. Recently, the prevalence of obesity has been increasing rapidly, reaching pandemic proportions. The causes of obesity are primarily lifestyle and malnutrition, mainly excessive calorie intake. There is still no consensus on the specifics of the influence of visceral obesity on histomorphological changes in white adipose tissue in animals of different ages. The aim of the work was to compare morphological changes in white adipose tissue in rats of different ages with visceral obesity. Materials and methods. The study was conducted on male Wistar rat’s line, aged 6 and 21 months. Visceral obesity in animals was modeled by keeping them on a high-calorie diet (580 kcal / 100 g) for 12 weeks, with an excess of fats and carbohydrates. Control animals were on a standard diet (330 kcal / 100 g). Histological preparations were prepared from the white adipose tissue using standard methods. Histomorphometry was performed using the computer program "ImageJ". Results. It was found that in the white adipose tissue of rats (regardless of their age) that received a high-calorie diet, an increase in the size of adipocytes occurs due to the accumulation of triglycerides in them. However, in young experimental rats, the number of adipocytes with a diameter of >100 μm was 10 times greater than in old animals. This indicates a hypertrophic type of obesity, and a more intense accumulation of lipids in adipocytes occurs at a young age. In addition, in the white adipose tissue of 6 month-old experimental rats, an increase in connective tissue was noted. While in 21 month-old animals, the amount of connective tissue, on the contrary, decreased. A decrease in white adipose tissue vascularization was observed in both experimental groups of rats. Conclusions. The intensity of morphological changes in the white adipose tissue depended on the degree of obesity and the age of the animals. In young rats, these changes were more pronounced than in older animals. These data are of interest for practical medicine in the development of new effective methods for the prevention and treatment of visceral obesity in patients of different ages.