[Biochemical markers of the functional state of liver in rats fed diets with different protein and sucrose content].

ABSTRACT

The study of mechanisms of the metabolic disorders in conditions of deficiency or excess of individual nutrients in the diet is a live issue. The influence of the simultaneous excess sucrose intake and protein deficiency in the diet on the functional state of the liver remains poorly understood. The aim of the research was to study the rate of generation of the superoxide radicals, the content of triglycerides and glycogen in the liver, as well as the activity of enzymatic markers of the liver state in rats fed diets with different protein and sucrose content. Material and methods. The studies were conducted over 28 days on 48 white non-linear rats, randomized into 4 groups 1 - animals fed full-value semi-synthetic ration (14% protein); 2 - animals receiving low-protein ration (4.7% protein); 3 - animals receiving high-sucrose diet (40% sucrose), 4 - animals receiving low-protein high-sucrose diet. Serum sorbitol dehydrogenase activity was determined by the kinetic method in the reaction of NADH-dependent reduction of D-fructose to D-sorbitol. Serum alanine aminotransferase activity and aspartate aminotransferase was evaluated using a kit of reagents (Ukraine). Results and discussion. It was found that in rats fed low protein diet, no changes in the de Ritis coefficient were observed, while the activity of sorbitol dehydrogenase in blood serum increased 1.7 fold. However, no changes in the rate of superoxide radical formation, as well as glycogen and triglyceride level in the liver were observed. In animals fed highsugar diet, a rise in the de Ritis coefficient on the background of increased serum sorbitol dehydrogenase activity (more than 3.5 times) was revealed. At the same time, the rate of the superoxide radical formation in the liver mitochondria enhanced by 3 fold, with an increased accumulation of glycogen and triglycerides. The most pronounced changes in liver state were observed in animals fed low-protein/high-sugar diet a marked increase in the de Ritis coefficient with a 5-fold increase in the activity of sorbitol dehydrogenase, and a 6-fold elevation in the intensity of the superoxide radical generation in liver mitochondria. The triglyceride content in the liver doubled, while the glycogen content remained at the level of control values. Conclusion. The data obtained represent disturbances of the functional liver state as a consequence of the relatively short-term excessive consumption of sucrose, especially in combination with a alimentary protein deficiency. It was found that the leading factor in the formation of destructive changes in the liver was excessive sucrose consumption, while the concomitant protein deficiency exacerbated the functional changes in hepatocytes.