Activity of the cytosolic enzymes of endogenous aldehydes catabolism under the conditions of different nutrients content in a diet

Abstract

The research was conducted to study the activity of aldehyde dehydrogenase (EC 1.2.1.3) and aldehyde reductase (EC 1.1.1.21), the levels of TBA reactive substances and protein carbonyl derivates in the cytosolic fraction of rat liver under the conditions of different dietary sucrose and protein content. The animals were distributed into the 4 experimental groups: group I — animals receiving full-value semi-synthetic feed (control group); group II — animals on a low-protein diet (LPD); III group — animals on a high-sucrose diet (HS); IV group — animals on a low-protein and high-sucrose diet (LPD/HS). It was found that in animals under conditions of dietary protein deficiency, there was a two-fold increase in the levels of TBA reactive substances and protein carbonyl derivates in the liver cytosolic fraction against the absence of changes in the aldehyde reductase and aldehyde dehydrogenase activity. At the same time, in animals on a high-sucrose diet, there was a significant accumulation of the TBA reactive substances and carbonyl derivatives in the liver cytosolic fraction along with a 2–2.5-fold increase in both aldehyde reductase and aldehyde dehydrogenase activity. The maximum accumulation of the products of oxidative damage to proteins and lipids along with the insufficient activation of the enzymes ensuring their catabolism can be considered as one of the possible mechanisms of liver cell damage under conditions of the low-protein/high-sucrose diet. The obtained results open new prospects for future studies of the mechanisms of endogenous aldehydes detoxification and further development of a strategy for the correction of metabolic liver disorders under the conditions of nutrient imbalance.