Effects of a high-carbohydrate high-fat diet on liver morphology in young and old rats

Abstract

The liver is a complex metabolic organ that, through the regulation of energy metabolism, maintains the homeostasis of the whole organism.Aim: To establish the morphological changes in hepatocytes and the expression of endothelial vascular factor in a high-carbohydrate high-fat diet (HCHFD) depending on age.Material and Methods. A histological study of the liver was carried out in four groups of male Wistar rats: 1st group – 5-month-old animals on a standard diet; 2nd  group – 5-month-old animals on HCHFD for 90 days (from 2 months of age); 3rd  group – 18-month-old animals on a standard diet; 4th  group – 18-month-old animals on HCHFD for 90 days (from 15 months of age). Using morphometric methods, the specific volumes (%) of unchanged and binuclear hepatocytes, sinusoidal capillaries, inflammatory infiltrates, and foci of fibrosis in the liver were determined. The expression of vascular endothelial growth factor (VEGF) in endothelial cells and hepatocytes was evaluated by immunohistochemical method. The concentration of cholesterol and triglycerides was determined by the enzymatic colorimetric method in the blood serum and in the liver.Results. A morphological study revealed a significant expansion of sinusoidal capillaries in groups 2 and 4. A statistically significant increase in the specific volume of hepatocytes with vacuolar inclusions, binuclear hepatocytes, fibrous foci and small inflammatory infiltrates was detected in the 4th  group. VEGF expression increased in hepatocytes of groups 2 and 4. Biochemical study found an increase in the concentration of triglycerides in the rats’ liver of the 4th  group. Thus, HCHFD, despite the pronounced signs of regeneration, increased age-related changes in the liver of old rats.