The Features of Energy Metabolism in Hepatocytes of Rats that Receive Diets with Different Nutrient Contents

Abstract

Abstract—The activities of isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, malate dehydrogenase, and NADH:ubiquinone reductase in the mitochondrial fraction from the liver tissue of rats fed diets with different sucrose and protein contents have been measured. In animals that received a high-sucrose diet, isocitrate dehydrogenase and malate dehydrogenase activities tend to decline and α-ketoglutarate dehydrogenase activity decreased by a factor of 2.5. Interestingly, the NADH:ubiquinone reductase activity remains at the control level in animals that are fed the high-sucrose diet. In the mitochondrial fraction from the liver tissue of rats that receive a high-sucrose–low-protein diet, the activities of NAD+-dependent dehydrogenases of the Krebs cycle decrease considerably, and the activity of NADH:ubiquinone reductase decreased as well, being more than 2.5 times lower than in the control. This may be one of the steps in the mechanism by which energy generated in the cell is regulated when the sucrose : protein ratio in the diet is imbalanced. These results can be used to develop a strategy for the correction of metabolic disturbances associated with nutrient contents in the diet.