glutaminase and Protein-Energy-Malnutrition

The activity of important glycolytic enzymes (hexokinase, phosphofructokinase, aldolase, phosphohexoseisomerase, pyruvate kinase and lactate dehydrogenase) and glutaminolytic enzymes (phosphate-dependent glutaminase) was determined in the thymus and mesenteric lymph nodes of Wistar rats submitted to protein malnutrition (6% protein in the diet rather than 20%) from conception to 12 weeks after birth. The wet weight (g) of the thymus and mesenteric lymph nodes decreased due to protein malnutrition by 87% (from 0.30 +/- 0.05 to 0.04 +/- 0.01) and 75% (0.40 +/- 0.04 to 0.10 +/- 0.02), respectively. The protein content was reduced only in the thymus from 102.3 +/- 4.4 (control rats) to 72.6 +/- 6.6 (malnourished rats). The glycolytic enzymes were not affected by protein malnutrition, but the glutaminase activity of the thymus and lymph nodes was reduced by half in protein-malnourished rats as compared to controls. This fact may lead to a decrease in the cellularity of the organ and thus in its size, weight and protein content.

Topics: Animals; Dietary Proteins; Fructose-Bisphosphate Aldolase; Glucose; Glucose-6-Phosphate Isomerase; Glutaminase; Glutamine; Glycolysis; Hexokinase; L-Lactate Dehydrogenase; Lymph Nodes; Male; Phosphofructokinase-1; Protein-Energy Malnutrition; Pyruvate Kinase; Rats; Rats, Wistar; Thymus Gland

The erythrocyte enzymes of glutamic acid metabolism (glutaminase I, glutaminase II, glutamic acid decarboxylase, glutamine synthetase, and transaminases) and related amino acids (glutamine, glutamic acid, aspartic acid, alanine, and gamma-aminobutyric acid) were estimated in 69 children with protein-energy malnutrition, 13 with nephrosis, and 10 with Indian childhood cirrhosis. Twenty-one apparently healthy children served as controls. There was a significant increase in the activities of erythrocytic glutaminase I, glutaminase II, glutamic acid decarboxylase, and glutamine synthetase in all the three hypoproteinemic states, while the activities of the transaminases showed a decrease in all the conditions. The concentrations of all the amino acids were significantly increased in both the varieties of protein-energy malnutrition (edematous and nonedematous). In nephrosis and Indian childhood cirrhosis, aspartic acid, alanine, and gamma-aminobutyric acid showed a significant rise. The concentration of glutamic acid was also significantly increased in nephrosis. The observations of the present study suggest an increase in intracellular production of glutamic acid in hypoproteinemia.

Topics: Alanine Transaminase; Amino Acids; Aspartate Aminotransferases; Child, Preschool; Erythrocytes; Glutamate Decarboxylase; Glutamate-Ammonia Ligase; Glutamates; Glutaminase; Humans; Infant; Liver Cirrhosis; Nephrosis; Protein-Energy Malnutrition; Proteins