PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 9733611-1 1998 Acute stresses such as trauma or endotoxemia augment GLN demand and are associated with increased release of this amino acid from skeletal muscle and lung as well as increased expression of glutamine synthetase (GS, the principal enzyme of GLN synthesis) in these tissues. Glutamine 240-243 glutamate-ammonia ligase Rattus norvegicus 190-210 9733611-3 1998 We hypothesized that the expression of GS in response to an acute stress would be altered in tumor-bearing rats (TBR) experiencing severe cachexia and therefore a previously heightened GLN demand. Glutamine 185-188 glutamate-ammonia ligase Rattus norvegicus 39-41 9624228-0 1998 Glutamine metabolism in the gastrointestinal tract of the rat assess by the relative activities of glutaminase (EC 3.5.1.2) and glutamine synthetase (EC 6.3.1.2). Glutamine 0-9 glutamate-ammonia ligase Rattus norvegicus 128-148 9624228-1 1998 The activities of the two key enzyme involved in glutamine metabolism, glutaminase (EC 3.5.1.2) and glutamine synthetase (EC 6.3.1.2), have been measured in the various tissues of the gastrointestinal (GI) tract of the rat, from the mouth to the rectum. Glutamine 49-58 glutamate-ammonia ligase Rattus norvegicus 100-120 9752723-1 1998 Glutamine synthetase, the enzyme that catalyzes the ATP-dependent conversion of glutamate and ammonia into glutamine, is expressed in a tissue-specific and developmentally controlled manner. Glutamine 107-116 glutamate-ammonia ligase Rattus norvegicus 0-20 9752723-3 1998 Glutamine synthetase protein stability is more than 10-fold reduced by its product glutamine and by covalent modifications. Glutamine 83-92 glutamate-ammonia ligase Rattus norvegicus 0-20 9495576-1 1997 Glutamine synthetase catalyses the formation of L-Gln from L-Glu and NH4+. Glutamine 48-53 glutamate-ammonia ligase Rattus norvegicus 0-20 9122259-4 1997 The time courses of glutamate and glutamine C-4 labeling were fitted to a mathematical model to yield TCA cycle rate (V(TCA)) and the flux from glutamate to glutamine through the glutamine synthetase pathway (V(gln)). Glutamine 34-43 glutamate-ammonia ligase Rattus norvegicus 179-199 9095109-4 1997 De novo synthesis of glutamine is regulated by the expression of the enzyme glutamine synthetase (GS). Glutamine 21-30 glutamate-ammonia ligase Rattus norvegicus 76-96 8997226-1 1996 Glutamine synthetase (GS) is a glucocorticoid-inducible enzyme that has a key role for glutamine synthesis in muscle. Glutamine 87-96 glutamate-ammonia ligase Rattus norvegicus 0-20 8945950-12 1996 However, glutamine regulation of GS appears complex and may involve more regulators than muscle glutamine concentration alone. Glutamine 9-18 glutamate-ammonia ligase Rattus norvegicus 33-35 8967483-0 1996 Glutamine interferes with glucocorticoid-induced expression of glutamine synthetase in skeletal muscle. Glutamine 0-9 glutamate-ammonia ligase Rattus norvegicus 63-83 8967483-7 1996 Moreover, in all muscle types studied, glutamine infusion diminished glucocorticoid effects on GS enzyme activity to 131-159% and on GS mRNA to 110-200% of the values in saline-treated controls. Glutamine 39-48 glutamate-ammonia ligase Rattus norvegicus 95-97 8967483-8 1996 These data demonstrate that glutamine infusion results in inhibiting GS expression, but the absence of changes in muscle glutamine concentration suggests the interplay of additional regulators of the GS gene. Glutamine 28-37 glutamate-ammonia ligase Rattus norvegicus 69-71 8848339-1 1996 Glutamine synthetase (GS) is a key enzyme involved in the endogenous biosynthesis of glutamine, an amino acid known to be essential for small intestinal metabolism and function. Glutamine 85-94 glutamate-ammonia ligase Rattus norvegicus 0-20 8676531-11 1996 The glutamine-free diet resulted in an increase of the lung glutamine synthetase activity and decrease in muscle glutamine content by the 28th day of the diet. Glutamine 4-13 glutamate-ammonia ligase Rattus norvegicus 60-80 9053810-2 1996 Ammonia is rapidly incorporated into glutamine by glutamine synthetase localized in astrocytes. Glutamine 37-46 glutamate-ammonia ligase Rattus norvegicus 50-70 8772537-1 1996 During septic states efflux of glutamine from the lung increases, a response sustained by an increase in glutamine synthetase (IGS) activity. Glutamine 31-40 glutamate-ammonia ligase Rattus norvegicus 105-125 7638749-2 1995 Lung glutamine release is increased markedly in patients with sepsis, and in rat models injection of endotoxin causes up-regulation of glutamine synthetase (GS), the principal enzyme of glutamine synthesis. Glutamine 5-14 glutamate-ammonia ligase Rattus norvegicus 135-155 7638749-2 1995 Lung glutamine release is increased markedly in patients with sepsis, and in rat models injection of endotoxin causes up-regulation of glutamine synthetase (GS), the principal enzyme of glutamine synthesis. Glutamine 5-14 glutamate-ammonia ligase Rattus norvegicus 157-159 7638749-2 1995 Lung glutamine release is increased markedly in patients with sepsis, and in rat models injection of endotoxin causes up-regulation of glutamine synthetase (GS), the principal enzyme of glutamine synthesis. Glutamine 135-144 glutamate-ammonia ligase Rattus norvegicus 157-159 7630137-1 1995 During stress states, organismal glutamine production is augmented secondary to an increase in the activity of glutamine synthetase (GS) in the lung and skeletal muscle. Glutamine 33-42 glutamate-ammonia ligase Rattus norvegicus 111-131 8551643-3 1995 Because glutamine is an important precursor for nucleic acids biosynthesis, we hypothesized that GS is preferentially expressed in the crypt region, which contains the rapidly proliferating cells in the small intestine. Glutamine 8-17 glutamate-ammonia ligase Rattus norvegicus 97-99 7826349-3 1995 Further glutamine synthesis was inhibited by intraperitoneal injection of methionine-DL-sulphoximine, an inhibitor of glutamine synthetase, and the infusate was changed to 14NH4+ during observation of decrease in brain [5-15N]glutamine due to PAG and other glutamine utilization pathways. Glutamine 8-17 glutamate-ammonia ligase Rattus norvegicus 118-138 8188174-3 1994 It has been postulated that the osmotic effects of glutamine, generated in astrocytes from ammonia and glutamate in a reaction catalyzed by glutamine synthetase, could mediate brain swelling. Glutamine 51-60 glutamate-ammonia ligase Rattus norvegicus 140-160 7906101-3 1994 Since the glucocorticoids play an important role in regulating interorgan glutamine metabolism during catabolic states, we hypothesized that these hormones induce the expression of gut mucosal glutamine synthetase (GS), the enzyme that catalyzes the intracellular biosynthesis of glutamine. Glutamine 74-83 glutamate-ammonia ligase Rattus norvegicus 193-213 7906101-3 1994 Since the glucocorticoids play an important role in regulating interorgan glutamine metabolism during catabolic states, we hypothesized that these hormones induce the expression of gut mucosal glutamine synthetase (GS), the enzyme that catalyzes the intracellular biosynthesis of glutamine. Glutamine 74-83 glutamate-ammonia ligase Rattus norvegicus 215-217 7906101-3 1994 Since the glucocorticoids play an important role in regulating interorgan glutamine metabolism during catabolic states, we hypothesized that these hormones induce the expression of gut mucosal glutamine synthetase (GS), the enzyme that catalyzes the intracellular biosynthesis of glutamine. Glutamine 193-202 glutamate-ammonia ligase Rattus norvegicus 215-217 7904125-5 1993 Depriving myotubes of glutamine did not alter the kinetics of uptake of amino acid transport systems A, ASC, or L. Glutamine deprivation resulted in a threefold increase in glutamine synthetase activity, whereas glutaminase activity remained unchanged. Glutamine 115-124 glutamate-ammonia ligase Rattus norvegicus 173-193 7904125-6 1993 System Nm and glutamine synthetase appear to undergo adaptive upregulation in glutamine-deprived muscle cells to compensate for the reduced exogenous glutamine supply. Glutamine 78-87 glutamate-ammonia ligase Rattus norvegicus 14-34 8104402-4 1993 Alterations in glutaminase and glutamine synthetase following aluminum exposure caused increased intracellular glutamine levels, decreased intracellular glutamate levels, and increased conversion of glutamate to glutamine and the release of the latter into the extracellular space. Glutamine 111-120 glutamate-ammonia ligase Rattus norvegicus 31-51 8099476-6 1993 Simultaneously, the activity of glutamine synthetase (GS), the principal enzyme of de novo glutamine biosynthesis, increased more than twofold. Glutamine 32-41 glutamate-ammonia ligase Rattus norvegicus 54-56 8099476-9 1993 Glutamine feeding increased muscle glutamine concentrations and glutamine synthetase specific activity. Glutamine 0-9 glutamate-ammonia ligase Rattus norvegicus 64-84 1363344-6 1992 Nevertheless, the increase in the concentration of glutamine in soleus muscle following ethanol administration is of interest and may be mediated via modulation of the glutamine transporter and/or the activity of glutamine synthetase in vivo. Glutamine 51-60 glutamate-ammonia ligase Rattus norvegicus 213-233 1363168-1 1992 Glutamine synthetase (L-glutamate:ammonia ligase; EC 6.3.1.2), an enzyme catalysing the ATP-dependent formation of glutamine from glutamate and ammonia, was detected immunocytochemically only in glial (interstitial) cells of the superficial pineal gland of the rat. Glutamine 115-124 glutamate-ammonia ligase Rattus norvegicus 0-20 1674354-1 1991 Glutamine synthetase catalyzes the formation of glutamine from glutamate and ammonia. Glutamine 48-57 glutamate-ammonia ligase Rattus norvegicus 0-20 1881516-2 1991 Added 500-microM glutamine increased the rate of GABA synthesis by 50%, indicating that glutamate decarboxylase is not saturated in brain slices. Glutamine 17-26 glutamate-ammonia ligase Rattus norvegicus 88-111 1982459-7 1990 The results suggest: (1) astrocytes are highly efficient in the conversion of glutamate to glutamine; (2) induction of GS activity increases the rate of glutamate conversion to glutamine by astrocytes and the rate of glutamine release into the medium; (3) endogenous intracellular regulators of GS activity control the flux of glutamate through this enzymatic reaction; and (4) the composition of the medium alters the rate of glutamine synthesis from external glutamate. Glutamine 91-100 glutamate-ammonia ligase Rattus norvegicus 119-121 1982459-7 1990 The results suggest: (1) astrocytes are highly efficient in the conversion of glutamate to glutamine; (2) induction of GS activity increases the rate of glutamate conversion to glutamine by astrocytes and the rate of glutamine release into the medium; (3) endogenous intracellular regulators of GS activity control the flux of glutamate through this enzymatic reaction; and (4) the composition of the medium alters the rate of glutamine synthesis from external glutamate. Glutamine 177-186 glutamate-ammonia ligase Rattus norvegicus 119-121 1982459-7 1990 The results suggest: (1) astrocytes are highly efficient in the conversion of glutamate to glutamine; (2) induction of GS activity increases the rate of glutamate conversion to glutamine by astrocytes and the rate of glutamine release into the medium; (3) endogenous intracellular regulators of GS activity control the flux of glutamate through this enzymatic reaction; and (4) the composition of the medium alters the rate of glutamine synthesis from external glutamate. Glutamine 177-186 glutamate-ammonia ligase Rattus norvegicus 119-121 1982459-7 1990 The results suggest: (1) astrocytes are highly efficient in the conversion of glutamate to glutamine; (2) induction of GS activity increases the rate of glutamate conversion to glutamine by astrocytes and the rate of glutamine release into the medium; (3) endogenous intracellular regulators of GS activity control the flux of glutamate through this enzymatic reaction; and (4) the composition of the medium alters the rate of glutamine synthesis from external glutamate. Glutamine 177-186 glutamate-ammonia ligase Rattus norvegicus 119-121 1977090-1 1990 Glutamine synthetase (GS) is the key enzyme in cerebral glutamine production. Glutamine 56-65 glutamate-ammonia ligase Rattus norvegicus 0-20 1977090-2 1990 Understanding the regulation of the expression of GS is important for definition of the control of glutamine metabolism in brain. Glutamine 99-108 glutamate-ammonia ligase Rattus norvegicus 50-52 1968957-6 1990 The greater stimulation of GABA synthesis by glutamine indicates that the GAD-containing compartment is more accessible to extrasynaptosomal glutamine than glutamate. Glutamine 45-54 glutamate-ammonia ligase Rattus norvegicus 74-77 1968957-6 1990 The greater stimulation of GABA synthesis by glutamine indicates that the GAD-containing compartment is more accessible to extrasynaptosomal glutamine than glutamate. Glutamine 141-150 glutamate-ammonia ligase Rattus norvegicus 74-77 2331991-4 1990 Conversely, during exposure to hypertonic media, net glutamine release from the liver increased due to inhibition of glutaminase flux and slight stimulation of flux through glutamine synthetase. Glutamine 53-62 glutamate-ammonia ligase Rattus norvegicus 173-193 1973271-1 1990 The method for the assay of glutamine synthetase (GlnS) relies on the gamma-glutamyl transferase reaction, i.e. the formation of glutamyl-gamma-hydroxamate from glutamine and hydroxylamine, and the chromatographic separation of the reaction product from the reactants. Glutamine 28-37 glutamate-ammonia ligase Rattus norvegicus 50-54 1982483-4 1990 We conclude that the increase in brain water content is linked to the glutamine accumulation derived from the detoxification of ammonia by glutamine synthetase. Glutamine 70-79 glutamate-ammonia ligase Rattus norvegicus 139-159 34681786-2 2021 We hypothesized that the effect of MSO results from a) glutamine synthetase block-mediated inhibition of conversion of Glu/Gln precursors to neurotransmitter Glu, and/or from b) altered synaptic Glu release. Glutamine 123-126 glutamate-ammonia ligase Rattus norvegicus 55-75 2573391-4 1989 This also suggests that glutamine utilization was, at least in part, masked by concomitant synthesis of glutamine from endogenous substrates via glutamine synthetase. Glutamine 104-113 glutamate-ammonia ligase Rattus norvegicus 145-165 2573391-6 1989 Addition of vasopressin (10(-7) M) led to a marked increase in glutamine removal by a dual mechanism: it accelerated flux through glutaminase, the enzyme which initiates the hepatic degradation of glutamine, and inhibited flux through glutamine synthetase. Glutamine 63-72 glutamate-ammonia ligase Rattus norvegicus 235-255 2900464-8 1988 Therefore, glucocorticoids seem essential for promoting muscle glutamine production in starvation probably by inducing the activity of glutamine synthetase. Glutamine 63-72 glutamate-ammonia ligase Rattus norvegicus 135-155 2879838-11 1987 Our data also show that some portal vein-derived ammonia is metabolized to glutamine in the rat liver, but the amount is small (approximately 7% of that metabolized to urea) in part because liver glutamine synthetase is located in a small population of perivenous cells "downstream" from the urea cycle-containing periportal cells. Glutamine 75-84 glutamate-ammonia ligase Rattus norvegicus 196-216 2870781-0 1986 Effect of removal of glutamine and addition of dexamethasone on the activities of glutamine synthetase, ornithine decarboxylase and lactate dehydrogenase in primary cultures of forebrain and cerebellar astrocytes. Glutamine 21-30 glutamate-ammonia ligase Rattus norvegicus 82-102 2870781-3 1986 Treatment with dexamethasone or removal of glutamine from the culture medium caused a marked increase in the specific activity of GS. Glutamine 43-52 glutamate-ammonia ligase Rattus norvegicus 130-132 2869396-9 1986 Glutamine synthesis in skeletal muscle may be regulated primarily by the availability of ammonia, which is associated with the degradation of adenine nucleotides, and secondarily by the amount of glutamine synthetase and glutamate in the tissue. Glutamine 0-9 glutamate-ammonia ligase Rattus norvegicus 196-216 2865140-7 1985 In experiments with and without methionine sulfoximine and in the absence of added glutamine, the glutamine content in the small perivenous hepatocyte population containing glutamine synthetase is estimated to be about 3.5 mumol/g wet weight and that in the periportal hepatocytes as low as 0.1 mumol/g wet weight. Glutamine 98-107 glutamate-ammonia ligase Rattus norvegicus 173-193 2865284-7 1985 Periportal glutaminase and perivenous glutamine synthetase are simultaneously active, resulting in an intercellular (as opposed to intracellular) glutamine cycle, being under the control of hormones, pH and portal ammonia and glutamine concentrations. Glutamine 146-155 glutamate-ammonia ligase Rattus norvegicus 38-58 6146632-4 1984 Glutamine synthetase activity was increased following incubation (1) in glutamine-free medium (threefold); (2) in medium containing high glutamic acid concentrations (fourfold); and (3) in medium supplemented with dexamethasone (threefold). Glutamine 72-81 glutamate-ammonia ligase Rattus norvegicus 0-20 6131695-7 1983 Glutamine synthetase flux was increased by ammonium ions, but this activation was partly overcome by increasing portal glutamine concentrations. Glutamine 119-128 glutamate-ammonia ligase Rattus norvegicus 0-20 6131695-8 1983 Glutamine synthetase flux was slightly increased by glucagon at portal glutamine concentrations of about 0.2-0.3 mM, but was strongly inhibited above 0.6 mMs. Glutamine 71-80 glutamate-ammonia ligase Rattus norvegicus 0-20 6131695-10 1983 During experimental metabolic acidosis there was an increased net release of glutamine by the liver, being due to opposing changes of flux through glutaminase and glutamine synthetase. Glutamine 77-86 glutamate-ammonia ligase Rattus norvegicus 163-183 6131695-11 1983 Conversely, an increased glutamine uptake by the liver during metabolic alkalosis was observed due to an inhibition of glutamine synthetase and an activation of glutaminase. Glutamine 25-34 glutamate-ammonia ligase Rattus norvegicus 119-139 24873689-0 1983 Developing rat cerebellum: Glutamine and glutamate influx correlated to the cellular distribution of glutamine synthetase. Glutamine 27-36 glutamate-ammonia ligase Rattus norvegicus 101-121 31191-0 1978 Effects of glutamine, methionine sulfone and dexamethasone on rates of synthesis of glutamine synthetase in cultured hepatoma cells. Glutamine 11-20 glutamate-ammonia ligase Rattus norvegicus 84-104 31191-1 1978 Glutamine synthetase (EC 6.3.1.2) activity of hepatoma tissue culture cells is elevated by corticosteroids and depressed by glutamine (Kulka, R.G., Tomkins, G.M. Glutamine 124-133 glutamate-ammonia ligase Rattus norvegicus 0-20 31191-5 1978 The transfer of cells from high (1--5 mM) to low (0.2--0.4 mM) concentrations of glutamine causes a marked increase in glutamine synthetase activity. Glutamine 81-90 glutamate-ammonia ligase Rattus norvegicus 119-139 31191-6 1978 The addition of a glutamine antagonist, methionine sulfone (1 mM) to cells suspended in high (1 mM) concentrations of glutamine also causes an increase of glutamine synthetase activity which is greater than that elicited by the transfer of cells to low concentrations of glutamine. Glutamine 18-27 glutamate-ammonia ligase Rattus norvegicus 155-175 31191-6 1978 The addition of a glutamine antagonist, methionine sulfone (1 mM) to cells suspended in high (1 mM) concentrations of glutamine also causes an increase of glutamine synthetase activity which is greater than that elicited by the transfer of cells to low concentrations of glutamine. Glutamine 118-127 glutamate-ammonia ligase Rattus norvegicus 155-175 31191-6 1978 The addition of a glutamine antagonist, methionine sulfone (1 mM) to cells suspended in high (1 mM) concentrations of glutamine also causes an increase of glutamine synthetase activity which is greater than that elicited by the transfer of cells to low concentrations of glutamine. Glutamine 118-127 glutamate-ammonia ligase Rattus norvegicus 155-175 83141-0 1978 Effect of glutamine on the degradation of glutamine synthetase in hepatoma tissue-culture cells. Glutamine 10-19 glutamate-ammonia ligase Rattus norvegicus 42-62 83141-1 1978 In certain lines of hepatoma tissue-culture cells, the extracellular glutamine concentration regulates the specific activity of glutamine synthetase. Glutamine 69-78 glutamate-ammonia ligase Rattus norvegicus 128-148 83141-2 1978 By quantifying the radioactivity in immunoprecipitated glutamine synthetase on polyacrylamide gels, we found that the rate of degradation, but not of synthesis, of glutamine synthetase is a sensitive function of extracellular glutamine. Glutamine 55-64 glutamate-ammonia ligase Rattus norvegicus 164-184 8212-0 1976 Glutamine-stimulated modification and degradation of glutamine synthetase in hepatoma tissue culture cells. Glutamine 0-9 glutamate-ammonia ligase Rattus norvegicus 53-73 8212-3 1976 Immunotitrations of HTC cell extracts demonstrate that in cells incubated in high concentrations (5 mM) of glutamine, a cross-reacting form of GS with a decreased enzyme-specific activity accumulates. Glutamine 107-116 glutamate-ammonia ligase Rattus norvegicus 143-145 8212-4 1976 On prolonged incubation of cells in high glutamine, there is net degradation of GS to form immunologically inactive products. Glutamine 41-50 glutamate-ammonia ligase Rattus norvegicus 80-82 2155-11 1975 It was concluded that: (a) the alanine aminotransferase and the glutamine synthetase pathways respectively were responsible for 80% of the alanine and glutamine released into the circulation by the extrasplanchnic tissues, and extrahepatic proteolysis could account for a maximum of 20%; (b) alanine formation by the peripheral tissues was dependent on availability of pyruvate and not of glutamate; (c) glutamate availability could influence glutamine formation subject, possibly, to renal control. Glutamine 151-160 glutamate-ammonia ligase Rattus norvegicus 64-84 240712-0 1975 Specificity of the glutamine-binding site involved in the reguation of glutamine-synthetase activity in hepatoma tissue-culture cells. Glutamine 19-28 glutamate-ammonia ligase Rattus norvegicus 71-91 240712-1 1975 Glutamine accelerates the degradation of glutamine synthetase in hepatoma tissue culture cells. Glutamine 0-9 glutamate-ammonia ligase Rattus norvegicus 41-61 240712-3 1975 6-Diazo-5-oxo-L-norleucine, like glutamine depressed the activity of glutamine synthetase in hepatoma tissue culture cells. Glutamine 33-42 glutamate-ammonia ligase Rattus norvegicus 69-89 240712-8 1975 This observation is interpreted to mean that the glutamine-binding site involved in the regulation of glutamine synthetase activity of hepatoma tissue culture cells is not the active site of the enzyme. Glutamine 49-58 glutamate-ammonia ligase Rattus norvegicus 102-122 2463-4 1975 The results suggest that glutamine synthesis and degradation are regulated in the central nervous system by cyclic AMP and cortisol: Gamma aminoburyric acid and other compounds can modulate the activity of glutamine synthetase and glutaminase. Glutamine 25-34 glutamate-ammonia ligase Rattus norvegicus 206-226 4146508-2 1973 Two common ways of measuring the potential for glutamine synthesis in a tissue are the rates of formation of gamma-glutamylhydroxamate either by synthesis from glutamate (the glutamylhydroxamate synthetase reaction) or by transfer from glutamine (the glutamyltransferase reaction); it has not been established, however, that either reaction is a specific measure of glutamine synthetase. Glutamine 47-56 glutamate-ammonia ligase Rattus norvegicus 366-386 34048864-5 2021 Downregulated glutamine synthetase (GS) activity, further supports disrupted glutamate metabolism compromising the glutamate-glutamine cycle. Glutamine 14-23 glutamate-ammonia ligase Rattus norvegicus 36-38 31313857-5 2019 We tested whether the glutamate-glutamine-cycle guides the lasting changes on plasticity observed after juvenile stress by blocking the astrocytic glutamate-degrading enzyme, glutamine synthetase (GS). Glutamine 32-41 glutamate-ammonia ligase Rattus norvegicus 175-195 27787475-2 2016 Glu is transformed into glutamine (Gln) by glutamine synthetase (GS) enzyme in glial cells. Glutamine 24-33 glutamate-ammonia ligase Rattus norvegicus 43-63 27787475-2 2016 Glu is transformed into glutamine (Gln) by glutamine synthetase (GS) enzyme in glial cells. Glutamine 35-38 glutamate-ammonia ligase Rattus norvegicus 43-63 23769890-5 2013 The results indicate that 77% of the newly appeared glutamine was formed via glutamine synthetase and 23% from endogenous sources; the stimulation of [3-(13)C]glutamine removal by MSO also strongly suggests the existence of a cycle between [3-(13)C]glutamine and [3-(13)C]glutamate. Glutamine 52-61 glutamate-ammonia ligase Rattus norvegicus 77-97 24257571-1 2013 BACKGROUND AND OBJECTIVE: Muscle is the major site for glutamine synthesis via glutamine synthetase (GS). Glutamine 55-64 glutamate-ammonia ligase Rattus norvegicus 79-99 21780187-1 2011 Glutamine synthetase (GS) is an astrocytic enzyme, which catalyzes the synthesis of glutamine from glutamate and ammonia. Glutamine 84-93 glutamate-ammonia ligase Rattus norvegicus 0-20 21338644-5 2011 In order to determine the participation of glutamine synthetase in the appearance of new glutamine molecules with glutamine as substrate, brain slices were incubated with [3-13C]glutamine in the presence of methionine sulfoximine, a specific inhibitor of glutamine synthetase. Glutamine 89-98 glutamate-ammonia ligase Rattus norvegicus 43-63 21338644-6 2011 Our results indicate that 36.5% of the new glutamine appeared was glutamine synthetase-dependent and 63.5% was formed from endogenous substrates. Glutamine 43-52 glutamate-ammonia ligase Rattus norvegicus 66-86 21193003-2 2011 Glutamine synthetase (GS) is highly expressed by astrocytes, and serves a neuroprotective function by converting cytotoxic glutamate and ammonia into glutamine. Glutamine 150-159 glutamate-ammonia ligase Rattus norvegicus 0-20 20557426-1 2010 Glutamine synthetase (GS) forms glutamine by catalyzing the ATP-dependent amidation of glutamate. Glutamine 32-41 glutamate-ammonia ligase Rattus norvegicus 0-20 20557426-8 2010 These results imply that GS expression in neurones occurs in response to a reduced availability of glutamine from astrocytes, and that neuronal GS expression represents a default phenotype which is normally suppressed via direct contacts with astrocytes. Glutamine 99-108 glutamate-ammonia ligase Rattus norvegicus 25-27 19299450-3 2009 Here we report that in the arcuate nucleus estradiol significantly increased the protein levels of the two enzymes in the glutamate-glutamine cycle, glutamine synthetase and glutaminase. Glutamine 132-141 glutamate-ammonia ligase Rattus norvegicus 149-169 17499397-0 2007 Does concomitant glucose and glutamine supplementation change the response of glutamine synthetase to fasting in healthy adult rats? Glutamine 29-38 glutamate-ammonia ligase Rattus norvegicus 78-98 17499397-1 2007 BACKGROUND & AIMS: Glutamine synthetase (GS), a key enzyme in the glutamine synthesis, is thus crucial in glutamine homeostasis. Glutamine 70-79 glutamate-ammonia ligase Rattus norvegicus 23-43 17499397-1 2007 BACKGROUND & AIMS: Glutamine synthetase (GS), a key enzyme in the glutamine synthesis, is thus crucial in glutamine homeostasis. Glutamine 70-79 glutamate-ammonia ligase Rattus norvegicus 45-47 17499397-1 2007 BACKGROUND & AIMS: Glutamine synthetase (GS), a key enzyme in the glutamine synthesis, is thus crucial in glutamine homeostasis. Glutamine 110-119 glutamate-ammonia ligase Rattus norvegicus 23-43 17499397-1 2007 BACKGROUND & AIMS: Glutamine synthetase (GS), a key enzyme in the glutamine synthesis, is thus crucial in glutamine homeostasis. Glutamine 110-119 glutamate-ammonia ligase Rattus norvegicus 45-47 17202437-1 2007 BACKGROUND: Glutamine synthetase (GS), a key enzyme in the production of glutamine, is preserved in rat skeletal muscle during aging but is increased with advanced age in vivo. Glutamine 73-82 glutamate-ammonia ligase Rattus norvegicus 12-32 17202437-1 2007 BACKGROUND: Glutamine synthetase (GS), a key enzyme in the production of glutamine, is preserved in rat skeletal muscle during aging but is increased with advanced age in vivo. Glutamine 73-82 glutamate-ammonia ligase Rattus norvegicus 34-36 17202437-8 2007 The up-regulated GS activity was decreased by an exogenous supply of glutamine only if intramuscular glutamine was depleted; this was confirmed by studies in the fed state. Glutamine 69-78 glutamate-ammonia ligase Rattus norvegicus 17-19 17202437-8 2007 The up-regulated GS activity was decreased by an exogenous supply of glutamine only if intramuscular glutamine was depleted; this was confirmed by studies in the fed state. Glutamine 101-110 glutamate-ammonia ligase Rattus norvegicus 17-19 16484281-2 2006 Astrocytes may play a role in these manifestations because astrocytes are essential in the regulation of released glutamate and its conversion to glutamine through the enzyme glutamine synthetase (GS). Glutamine 146-155 glutamate-ammonia ligase Rattus norvegicus 175-195 16688719-1 2006 Glutamine synthetase (GS), localized to astrocyte is a key enzyme in the glutamate-glutamine pathway in the brain. Glutamine 83-92 glutamate-ammonia ligase Rattus norvegicus 0-20 16815492-1 2006 OBJECTIVE: Glutamine synthetase (GS), a key enzyme in the production of glutamine, is preserved in skeletal muscle during early aging (<24 mo). Glutamine 72-81 glutamate-ammonia ligase Rattus norvegicus 11-31 16815492-1 2006 OBJECTIVE: Glutamine synthetase (GS), a key enzyme in the production of glutamine, is preserved in skeletal muscle during early aging (<24 mo). Glutamine 72-81 glutamate-ammonia ligase Rattus norvegicus 33-35 16815492-11 2006 CONCLUSION: There is enhanced GS activity in old female and male rats suggesting a greater need for glutamine. Glutamine 100-109 glutamate-ammonia ligase Rattus norvegicus 30-32 16530878-1 2006 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. Glutamine 182-191 glutamate-ammonia ligase Rattus norvegicus 270-290 16530878-5 2006 RESULTS: Glutamine synthetase protein (but not gene) expression and enzyme activities were significantly up-regulated leading to increased de novo synthesis of glutamine and increased skeletal muscle capacity for ammonia removal in acute liver failure. Glutamine 160-169 glutamate-ammonia ligase Rattus norvegicus 9-29 15998438-10 2005 The production of glutamine in the periportal area is in agreement with recent reports about the presence of glutamine synthetase in Kupffer and endothelial cells. Glutamine 18-27 glutamate-ammonia ligase Rattus norvegicus 109-129 15896426-1 2005 BACKGROUND AND AIMS: In earlier studies, skeletal muscle glutamine synthetase (GS) activity was shown to be enhanced by fasting and glucocorticoids, and inhibited by exogenous glutamine (Gln) supplementation. Glutamine 187-190 glutamate-ammonia ligase Rattus norvegicus 57-77 15850218-1 2005 The influence of modified antineoplaston AS2-1 (with altered ratio of L-phenylalanine and L-glutamine derivatives, "Deglutam") on the activity of glutamine synthetase, glutaminase isoforms in the carcinosarcoma SM-1, tumor weight, per cent of the inhibition of tumor growth and blood impact index was investigated in rats with carcinosarcoma SM-1. Glutamine 90-101 glutamate-ammonia ligase Rattus norvegicus 146-166 12718445-2 2003 Manganese is a modulator and glutamine is the product of glutamine synthetase. Glutamine 29-38 glutamate-ammonia ligase Rattus norvegicus 57-77 12193680-3 2002 It was hypothesized that deprivation of dietary glutamine leads to intestinal disease that is exacerbated by inhibition of glutamine synthetase by methionine sulfoximine (MS). Glutamine 48-57 glutamate-ammonia ligase Rattus norvegicus 123-143 12126882-2 2002 In the central nervous system, glial cells contain enzymes related to the tricarboxylic acid and glutamine cycles: pyruvate carboxylase, glutamate dehydrogenase, and glutamine synthetase. Glutamine 97-106 glutamate-ammonia ligase Rattus norvegicus 166-186 11739103-1 2002 Glutamine synthetase, a key enzyme in the production of glutamine, is known to be induced by glucocorticoids and preserved in skeletal muscle during aging, but the effect of other steroids, such as sex steroids (progesterone, estradiol), is unknown in vivo. Glutamine 56-65 glutamate-ammonia ligase Rattus norvegicus 0-20 11433423-2 2001 Ammonium ions penetrate from blood to brain, where they form glutamine (Gln) in the reaction with glutamate catalyzed by an astroglia-specific enzyme, glutamine synthetase (GS). Glutamine 61-70 glutamate-ammonia ligase Rattus norvegicus 151-171 11433423-2 2001 Ammonium ions penetrate from blood to brain, where they form glutamine (Gln) in the reaction with glutamate catalyzed by an astroglia-specific enzyme, glutamine synthetase (GS). Glutamine 72-75 glutamate-ammonia ligase Rattus norvegicus 151-171 11191626-1 2000 Recently, a soluble factor produced by primary periportal hepatocytes and different from glutamine was found to completely block induction of glutamine synthetase (GS) by dexamethasone (DEX) in the liver cell line RL-ET-1G. Glutamine 89-98 glutamate-ammonia ligase Rattus norvegicus 142-162 11044634-1 2000 The metabolism of glutamine, the main respiratory fuel of enterocytes, is governed by the activity of glutaminase and glutamine synthetase. Glutamine 18-27 glutamate-ammonia ligase Rattus norvegicus 118-138 10362628-3 1999 In the lung, this discrepancy is caused by feedback destabilization of the GS protein by its product Gln. Glutamine 101-104 glutamate-ammonia ligase Rattus norvegicus 75-77 10362628-4 1999 It was hypothesized that muscle GS protein levels increase during stress only when the intracellular Gln pool has been depleted. Glutamine 101-104 glutamate-ammonia ligase Rattus norvegicus 32-34