CHANGES IN PROTEIN AND LIPID PEROXIDATION IN ORGANS OF HEPATOPANCREATOBILIARY SYSTEM, ENZYMATIC ANTIOXIDANTS IN RATS UNDER THE CONDITIONS OF DIETS WITH EXCESSIVE CARBOHYDRATES OR FATS
Authors: Tsymbala E. M. , Voronych-Semchenko N. M. 
Published: April 2022

Among the mechanisms of pathological processes development, in particular obesity, an important role belongs to the increase in the intensity of oxygen-dependent processes. It is known that the products of protein and lipid peroxidation can change the structure of the cell membrane, lead to denaturation of proteins and damage to amino acids. Accumulation of protein and lipid peroxidation products can inhibit oxidative phosphorylation and glycolysis, can cause tissue edema and worsen the course of inflammatory processes. Such changes may occur against the background of inertia or suppression of antioxidant reserves. The in-depth study of the obesity development against the background of high-carbohydrate or high-fat diets attracts attention.

The aim of the research was to study the peculiarities of indices of the oxygen-dependent processes and anti-radical protection of the body against the background of a high-calorie diet during the experiment. The study was performed using mature male rats on a diet with excessive amount of carbohydrates (experimental group 1) and fats (experimental group 2) and on a standard diet of vivarium (control group).

As a result of the study in the blood serum of experimental rats there was observed an increased content of products of the oxidative modification of proteins in the blood serum at 64.35% – 3.3-fold (p˂0.05), in liver tissues – 2.6-4.5-fold (p˂0.01) and pancreas at 67.86% – 5.6-fold (p˂0.05) regarding the control group data. Changes in lipoperoxidation indices were unidirectional. In particular, in the blood serum of animals on high-carbohydrate and high-fat diets there was an increase in the content of diene conjugates (DC) and products that react to thiobarbituric acid (TBA-AP) at 72.37% – 2.2-fold (p˂0.001), in the tissues of liver and pancreas – an increase in the level of TBA-AP at 44.07% – 6.0-fold (p˂0.01), respectively regarding the control. There were no significant differences found between the studied indices of protein and lipid peroxidation in animals of the experimental groups 1 and 2. The resulting changes may indicate a number of abnormalities (structural rearrangement of hepatocyte membranes, impaired cellular metabolism and energy metabolism, increased unsaturated fatty acids), which in turn can lead to the development of diabetes mellitus and obesity.

Activation of protein and lipid peroxidation occurred under the conditions of increased catalase activity at 2.5-3.4-fold (p˂0.05), ceruloplasmin content at 54,61-88,65% (р˂0,05), iron transferrin saturation at 43,58-51,28% (р˂0,01) against the background of reduced superoxide dismutase and glutathione reductase activity (at 26,84-83,34% р˂0,01) regarding the values in intact animals. The determined changes of antioxidant reserve did not depend on the diet type. Such changes may indicate a corresponding strain on the functional abilities of the antioxidant system during the increase in the intensity of oxidative stress under the conditions of obesity.

The resulting disorders reflect the development of oxidative stress and are the risk factors for structural adjustments and functional changes in the hepatopancreatobiliary system organs. Activation of the processes of free radical oxidation of proteins and lipids against the background of inhibition of antioxidant enzymes can play a significant role in the development of obesity complications, especially such as hypertension, atherosclerosis, heart failure, type 2 diabetes mellitus.