Measurement of glutamine synthetase activity in rat muscle by a colorimetric assay

Minet, R.; Villie, F; Marcollet, M.; Meynial-Denis, Dominique; Cynober, Luc

doi:10.1016/s0009-8981(97)00173-3

Cited by 69 publications

(50 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…GS activity was determined in cytosols from gastrocnemius muscle samples with a method described earlier (42,43), which measures the GS-dependent formation from glutamine of ␥-glutamyl hydroxamate, quantified spectrophotometrically by measurement of absorbance at 540 nm after 25 min of incubation at 37°C. GS activity was calculated with a molar extinction coefficient of 1.08 M/cm (44) and was expressed relative to cytosol protein content.…”

Section: Gs Assaymentioning

confidence: 99%

Illuminating the interrelated immune and endocrine adaptations after multiple exposures to short immobilization stress by in vivo blocking of IL-6

Smith¹,

Wilson²,

Louw³

et al. 2007

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

Intermittent psychological stress was induced in adult rats by 2 h/day of immobilization stress for 4 days, with or without blocking the function of IL-6 by using an anti-IL-6 antibody. Basal concentrations of serum corticosterone, IL-1β, IL-6, and TNF-α were assessed 24 h after the last intervention, as were levels of glucocorticoid receptors (GR) and activities of glucocorticoid-inducible enzymes (tyrosine aminotransferase and glutamine synthetase) in muscle and liver. Whole blood cultures were used to assess both spontaneous and LPS-induced reactivity of peripheral blood mononuclear cells. Stress increased corticosterone concentration in a manner partially modulated by IL-6. Serum IL-1β concentration was downregulated during stress when IL-6 was blocked ( P < 0.01). LPS-induced IL-6 secretion by peripheral blood mononuclear cells in vitro correlated positively with serum IL-1β concentration in antibody-treated groups, independently of stress ( R = 0.70 in nonstressed and R = 0.78 in stressed rats; both P < 0.05), whereas serum corticosterone concentration correlated positively with LPS-induced secretion of IL-6 only in control rats ( R = 0.66; P < 0.05). Reductions in liver GR levels indicated independent effects of stress (34.5%) and anti-IL-6 antibody (16.7%) and additive effects for both (62.5%). Similar results are reported for vastus muscle. Conversely, stress increased tyrosine aminotransferase and glutamine synthetase activities in muscle and liver with a significant ( P < 0.05) effect of anti-IL-6 antibody only seen in stressed livers. In conclusion, IL-6 plays a role in maintaining circulating IL-1β concentration after multiple exposures to stress, thus promoting a continued elevation of corticosterone release; in peripheral tissues, IL-6 antagonizes the effects of glucocorticoids, especially at the level of GR concentration.

show abstract

Section: Gs Assaymentioning

confidence: 99%

Illuminating the interrelated immune and endocrine adaptations after multiple exposures to short immobilization stress by in vivo blocking of IL-6

Smith¹,

Wilson²,

Louw³

et al. 2007

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

show abstract

“…Muscle glutamine was extracted as described by Sahlin, Katz and Broberg (1990), while glutamine concentration was determined as described by Lund (1985). The maximal activity of the enzyme glutamine synthetase (GS) in the liver and gastrocnemius muscle was determined according to Minet et al (1997).…”

Section: Biochemical Analysismentioning

confidence: 99%

Early weaning impairs body composition in male mice

Borges

Rogero

Pires

et al. 2009

Braz. J. Pharm. Sci.

View full text Add to dashboard Cite

This study aimed to evaluate the effect of early weaning on body composition and on parameters related to nutritional status in mice. The experimental group consisted of male Swiss Webster mice that were weaned early (at postnatal day fourteen) and fed an appropriate diet for growing rodents until postnatal day twenty-one (EW group). The control group consisted of male mice breastfed until postnatal day twenty-one (CON group). All animals were sacrificed on the twenty-first day of life. The EW group showed a decrease in liver and muscle protein content and concentration, brain protein concentration, brain DNA content and concentration, as well as liver and muscle protein/RNA ratio (p<0.05). Concerning body composition, the EW mice showed increased moisture content, increased moisture and lipid percentage, and a smaller percentage and content of protein and ash in the carcass (p<0.05). These results indicate that early weaning impairs body composition and parameters related to nutritional status, which may be explained by retarded chemical maturation processes. This data may contribute to the overall understanding of the influence of breastfeeding versus feeding with artificial milk on body composition and on nutritional status. Uniterms:Weaning. Body composition. Breastfeeding. Nutritional status.O presente estudo objetivou avaliar o efeito do desmame precoce sobre a composição corporal e sobre parâmetros indicativos do estado nutricional de camundongos. O grupo experimental consistiu de camundongos Swiss Webster, machos, desmamados precocemente (14º dia de vida) e alimentados com ração apropriada para roedores em crescimento até o 21º dia pós-natal (grupo DESM). O grupo controle consistiu de camundongos amamentados até o 21º dia pós-natal (grupo CON). Todos os animais foram sacrificados no 21º dia de vida. O grupo DESM apresentou redução da concentração e conteúdo hepático e muscular de proteínas, da concentração cerebral de proteínas, da concentração e conteúdo cerebral de DNA e da razão proteína/RNA hepática e muscular (p<0,05). Quanto à composição corporal, o grupo DESM apresentou maior conteúdo de umidade, maior percentual de umidade e lipídios e menor conteúdo e percentual de cinzas e proteína na carcaça (p<0,05). Os resultados indicam que o desmame precoce acarreta em prejuízo à composição corporal e a parâmetros indicativos do estado nutricional, o que pode estar relacionado ao retardo do processo de maturação química. Os dados do presente estudo podem contribuir para o entendimento da influência da alimentação com fórmulas infantis sobre a composição corporal e sobre o estado nutricional.Unitermos: Desmame. Composição corporal. Aleitamento materno. Estado nutricional.

show abstract

“…Fax: (732) 594 5468. 2 Abbreviations used: GS, glutamine synthetase; GRE, glucocorticoid response element; GT, ␥-glutamyl transferase; HSM, human skeletal muscle; ADP, adenosine 5Ј-diphosphate; TCA, trichloroacetic acid; DMEM, Dulbecco's modified Eagle's medium; FBS, fetal bovine serum; P/S, penicillin/streptomycin; PBS, phosphate-buffered saline; nbD, nonspecifically bound [ 3 as methylprednisolone and dexamethasone stimulate GS expression and activity in rat skeletal muscle (11,14).…”

mentioning

confidence: 99%

“…This method employs the use of labeled substrates and ion exchange chromatography to separate product from substrate, which limits its use as a convenient highthroughput assay. In comparison, enzyme activity can also be followed by use of the well-known and characterized ␥-glutamyl transfer reaction in which GS catalyzes the conversion of L-glutamine to the corresponding hydroxamate in the presence of hydroxylamine, catalytic quantities of ADP or ATP, and inorganic phosphate or arsenate (14,21,22,24). The ␥-glutamyl transfer activity of GS has been measured in cultured astroblasts from rat brain (24), where formation of the product glutamyl-␥-hydroxamate is monitored by HPLC.…”

mentioning

confidence: 99%

“…Furthermore, a colorimetric method can also be used to measure the ␥-glutamyl transferase activity of GS by determination of the reaction product glutamyl-␥-hydroxamate, which forms a purplish brown complex in the presence of trivalent iron (21,25). More recently, this colorimetric method was also used to measure glucocorticoid induced GS catalyzed ␥-glutamyl transferase (GT) activity in extracts of rat skeletal muscle tissue (14). However, the application of this method to measure GS activity in crude cell extracts requires the inclusion of appropriate controls since contaminating enzymes including glutaminases can also promote GT activity (21,26,27).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Colorimetric Detection of Glutamine Synthetase-Catalyzed Transferase Activity in Glucocorticoid-Treated Skeletal Muscle Cells

Santoro

Harris

Sitlani

2001

Analytical Biochemistry

View full text Add to dashboard Cite

Measurement of glutamine synthetase activity in rat muscle by a colorimetric assay

Cited by 69 publications

References 24 publications

Illuminating the interrelated immune and endocrine adaptations after multiple exposures to short immobilization stress by in vivo blocking of IL-6

Illuminating the interrelated immune and endocrine adaptations after multiple exposures to short immobilization stress by in vivo blocking of IL-6

Early weaning impairs body composition in male mice

Colorimetric Detection of Glutamine Synthetase-Catalyzed Transferase Activity in Glucocorticoid-Treated Skeletal Muscle Cells

Contact Info

Product

Resources

About