The aim of the present study was to evaluate the effect of cholera toxin on energy balance from intestinal glutamine metabolism and oxidation, glutamine-dependent sodium absorption, and cholera toxin-dependent ion flux. Cholera toxin-stimulated sodium and L-glutamine ileal transport and metabolism were studied in Ussing chambers. Glutamine (10 mM) transport and metabolism were simultaneously st...

Glutamine is the most abundant free amino acid in the human blood stream and is 'conditionally essential' to cells. Its intracellular levels are regulated both by the uptake of extracellular glutamine via specific transport systems and by its intracellular synthesis by glutamine synthetase (GS). Adding to the regulatory complexity, when extracellular glutamine is reduced GS protein levels rise....

The final products of the catabolism of arginine that can be utilized as nitrogen sources by Neurospora crassa are ammonium, glutamic acid, and glutamine. Of these compounds, only glutamine represses arginase and glutamine synthetase. We report here the isolation and characterization of a mutant of N. crassa whose arginase, glutamine synthetase, and amino acid accumulations are resistant to glu...

Glutamine is an important mitochondrial substrate implicated in the protection of cells from oxidant injury, but the mechanisms of its action are incompletely understood. Human pulmonary epithelial-like (A549) cells were exposed to 95% O2 for 4 days in the absence and presence of glutamine. Cell proliferation in normoxia was dependent on glutamine, and glutamine deprivation markedly accelerated...

Glutamine has a positive effect on ameliorating reproductive failure caused by porcine circovirus type 2 (PCV2). However, the mechanism by which glutamine affects PCV2 replication remains unclear. This study was conducted to investigate the effects of glutamine on PCV2 replication and its underlying mechanisms in vitro. The results show that glutamine promoted PK-15 cell viability. Surprisingly...

Chromatographic, kinetic, and regulatory properties of glutamine synthetase in rice were investigated. By DEAE-Sephacel column chromatography, two forms (glutamine synthetase 1 and glutamine synthetase 2) were identified in leaves and one form (glutamine synthetase R) was identified in roots. Purification on hydroxyapatite and gel electrophoresis showed that glutamine synthetase R was distinct ...

Oxidative decarboxylation of L-[1-14C]glutamine was studied in isolated chick and rat skeletal muscles incubated in the presence of glucose, insulin and plasma concentrations of amino acids. (1) The rate of oxidative decarboxylation of L-[1-14C]glutamine was high, and exceeded that of L-[1-14C]leucine in all muscles. (2) The rate of oxidative decarboxylation of L-[1-14C]glutamine increased with...

1. When isolated kidneys from fed rats were perfused with glutamine the rate of ammonia release at pH7.4 (110-360mumol/h per g dry wt.) was one to two times that of glutamine removal. Glucose formation from 5mm-glutamine was 16mumol/h per g. If kidneys were perfused with glutamine at pH7.1 (10-13mm-sodium bicarbonate) there was no increase in glutamine removal or in the formation of ammonia or ...

Introduction Glutamine is the source for most of the nitrogen in biosynthetic pathways because of its connection to carbohydrate metabolism via cr-oxoglutarate and glutamate. The enzymes that transfer nitrogen from the amide of glutamine to acceptor substrates in biosynthetic pathways are known as glutamine amidotransferases. Glutamine amidotransferases are a large and well studied family of en...