BACKGROUND Addition of glutamine to enteral nutrition formulas is consistently associated with a significant decrease in septic morbidity in critically ill patients, possibly related to the attenuation of gut dysfunction. This pilot study was undertaken to compare the effects of enteral administration of two glutamine-enriched formulas containing either additional free glutamine or glutamine-ri...

Glutamine is an important renal glucose precursor and energy provider. In order to advance our understanding of the underlying metabolic processes, we studied the metabolism of variously labelled [13C]glutamine and [14C]glutamine molecules and the effects of fasting in isolated rat renal proximal tubules. Absolute fluxes through the enzymes involved, including enzymes of four different cycles o...

Glutamine synthetase activity in Chinese hamster cells in tissue culture possesses properties identical with purified liver glutamine synthetase. The cellular level of enzyme is regulated by the concentration of glutamine in the growth media. Induction by removal of glutamine leads to an 8to IO-fold increase in enzyme activity within 48 hours. Repression is a much more rapid process. Half of th...

BACKGROUND/AIMS It has been proposed that, in acute liver failure, skeletal muscle adapts to become the principle organ responsible for removal of blood-borne ammonia by increasing glutamine synthesis, a reaction that is catalyzed by the cytosolic ATP-dependent enzyme glutamine synthetase. To address this issue, glutamine synthetase expression and activities were measured in skeletal muscle of ...

BACKGROUND Arginine plays a role in many different pathways in multiple cell types. Consequently, a shortage of arginine, caused by pathologic conditions such as cancer or injury, has the potential to disturb many cellular and organ functions. Glutamine is the ultimate source for de novo synthesis of arginine in humans via the intestinal-renal axis. Therefore, we hypothesized that parenteral gl...

In certain lines of hepatoma tissue culture (HTC) cells, glutamine synthetase (EC 6.3.1.2) specific activity is increased 2.5- to 3-fold by the addition of glucocorticoids to the growth media. Actinomycin D blocks both the induction and deinduction of glutamine synthetase by glucocorticoids, suggesting a requirement of RNA synthesis for both processes. Using an antiserum raised against purified...

Glutamine, the most abundant amino acid in the bloodstream, is the preferred fuel source for enterocytes and plays a vital role in the maintenance of mucosal growth. The molecular mechanisms regulating the effects of glutamine on intestinal cell growth and survival are poorly understood. Here, we show that addition of glutamine (1 mmol/l) enhanced rat intestinal epithelial (RIE)-1 cell growth; ...

The regulation of glutamine synthetase expression by dexamethasone was studied in rat skeletal muscles. Daily administration of dexamethasone caused striking enhancement of glutamine synthetase activity in plantaris, soleus, and diaphragm muscles. Northern blot analysis revealed that the dexamethasone-mediated increase of glutamine synthetase activity was associated with dramatically increased ...

Renal glutamine synthetase catalyzes the reaction of NH4+ with glutamate, forming glutamine and decreasing the ammonia available for net acid excretion. The purpose of the present study was to determine glutamine synthetase's specific cellular expression in the mouse kidney and its regulation by hypokalemia, a common cause of altered renal ammonia metabolism. Glutamine synthetase mRNA and prote...

BACKGROUND Glutamine is the most abundant free amino acid in the body. It modulates immune cell function and is an important energy substrate for cells in critically ill patients. Reduction of injury cardiac markers had been observed in patients receiving intravenous glutamine and in a pilot study with oral glutamine. The aim of this study was to analyze the effect of preoperative oral suppleme...