Alterations in glutamine synthetase activity in rat skeletal muscle are associated with advanced age

Pinel, Carole; Coxam, Véronique; Mignon, M; Taillandier, Daniel; Cubizolles, Christine; Lebecque, Patrice; Meynial-Denis, Dominique

doi:10.1016/j.nut.2006.05.005

Cited by 22 publications

(16 citation statements)

References 32 publications

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“…129 In contrast to these findings, Spindler 130 demonstrated that glutaminase, which is a key enzyme in liver nitrogen disposal, increased in caloric-restricted aged mice. This author also reported that glutamine synthetase decreased by about 40% in these conditions, which is in good agreement with the findings of Pinel et al 117 It is noteworthy that glutaminase was shown to be significantly increased only at 24 months in male Wistar rats, but at this age, 50% of them died.…”

Section: Impact Of Aging On Glutamine Synthesis In the Liversupporting

confidence: 90%

“…116 However, in very old rats aged 25 months (female rats, whose mean life expectancy is %27 months, with a maximum life span of 32 months), aging does not induce changes either in plasma or muscle glutamine concentrations (0.5960.13 vs 0.556 0.15 mM in plasma and 3.2160.60 vs 3.1860.85 mmol/g in muscle). 117 Advanced age in rats corresponds to an age of about 75-80 years in humans. Glutamine deficiency in bed rest in humans also alters monocyte or macrophage activity, decreases the formation of heatshock proteins, stimulates cell apoptosis, and shifts the cellular redox potential by altering glutathione synthesis in lymphocytes.…”

Section: Effect Of Aging On Whole-body Glutamine Metabolismmentioning

confidence: 99%

“…High levels, such as those reported in the 25-to 27-month-old rats, may be considered an indicator of stress and frailty and, thus, the need for more glutamine. 117 Moreover, glutamine synthetase in muscle is a longevity-related gene and increases with caloric restriction in mice. 21 Because glutamine synthetase activity increases with fasting, whatever the age of animals, 118 glutamine synthesis was compared directly in skeletal muscle from 2-[…”

Section: Effect Of Aging On Whole-body Glutamine Metabolismmentioning

confidence: 99%

“…In some very old female rats, low glutamine synthetase activity may be associated with longevity or may reflect a limitation of glutamine production due to extremely advanced age per se. 117 …”

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confidence: 99%

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Glutamine metabolism in advanced age

Meynial-Denis

2016

Nutr Rev

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Glutamine, reviewed extensively in the last century, is a key substrate for the splanchnic bed in the whole body and is a nutrient of particular interest in gastrointestinal research. A marked decrease in the plasma glutamine concentration has recently been observed in neonates and adults during acute illness and stress. Although some studies in newborns have shown parenteral and enteral supplementation with glutamine to be of benefit (by decreasing proteolysis and activating the immune system), clinical trials have not demonstrated prolonged advantages such as reductions in mortality or risk of infections in adults. In addition, glutamine is not able to combat the muscle wasting associated with disease or age-related sarcopenia. Oral glutamine supplementation initiated before advanced age in rats increases gut mass and improves the villus height of mucosa, thereby preventing the gut atrophy encountered in advanced age. Enterocytes from very old rats continuously metabolize glutamine into citrulline, which allowed, for the first time, the use of citrulline as a noninvasive marker of intestinal atrophy induced by advanced age.

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Section: Impact Of Aging On Glutamine Synthesis In the Liversupporting

confidence: 90%

Section: Effect Of Aging On Whole-body Glutamine Metabolismmentioning

confidence: 99%

Section: Effect Of Aging On Whole-body Glutamine Metabolismmentioning

confidence: 99%

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confidence: 99%

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Glutamine metabolism in advanced age

Meynial-Denis

2016

Nutr Rev

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“…No cérebro, é utilizada como um importante agente na redução da concentração de amônia, com consequente desintoxicação e síntese de glutamina para nova síntese de glutamato (9) . No pulmão e no músculo esquelético, é responsável pela manutenção da concentração de glutamina plasmática, sendo essencial em situações patológicas ou de estresse (13) . Nos rins, a glutamina sintetase é imprescindível para o controle do metabolismo do nitrogênio e manutenção do pH no organismo (12) .…”

Section: Considerações Metabólicas E Bioquímicas Da Glutaminaunclassified

Glutamina: aspectos bioquímicos, metabólicos, moleculares e suplementação

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Petry

Tirapegui

2009

Rev Bras Med Esporte

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A glutamina é o aminoácido livre mais abundante no plasma e no tecido muscular. Nutricionalmente é classificada como um aminoácido não essencial, uma vez que pode ser sintetizada pelo organismo a partir de outros aminoácidos. A glutamina está envolvida em diferentes funções, tais como a proliferação e desenvolvimento de células, o balanço acidobásico, o transporte da amônia entre os tecidos, a doação de esqueletos de carbono para a gliconeogênese, a participação no sistema antioxidante e outras. Por meio de técnicas de biologia molecular, estudos demonstram que a glutamina pode também influenciar diversas vias de sinalização celular, em especial a expressão de proteínas de choque térmico (HSPs). As HSPs contribuem para a manutenção da homeostasia da célula na presença de agentes estressores, tais como as espécies reativas de oxigênio (ERO). Em situações de elevado catabolismo muscular, como após exercícios físicos intensos e prolongados, a concentração de glutamina pode tornar-se reduzida. A menor disponibilidade desse aminoácido pode diminuir a resistência da célula a lesões, levando a processos de apoptose celular. Por essas razões, a suplementação com L-glutamina, tanto na forma livre, quanto como dipeptídeo, tem sido investigada. Alguns aspectos bioquímicos, metabólicos e mecanismos moleculares da glutamina, bem como os efeitos de sua suplementação, são abordados no presente trabalho.Palavras-chave: glutamina, exercício, HSP, suplementação, dipeptídeo. aBStRaCtGlutamine is the most frequent free amino acid in the serum and muscular tissue. Nutritionally, it is classified as a non-essential amino acid, once it can be synthesized by the body from other amino acids. Glutamine is involved in different functions, such as cell proliferation and development, basic acid balance, ammonia transportation between tissues, carbon skeleton donation to the gluconeogenesis, participation in the antioxidant system, among others. Molecular biology techniques show that it may also influence several cell signaling ways, especially the expression of heat shock proteins (HSP). The HSPs contribute to the maintenance of the cellular homeostasis in the presence of stress agents such as oxygen reactive species (ORE). In situations of high cellular catabolism, as after intense and prolonged physical exercises, the glutamine concentration may become reduced. Lower availability of this amino acid may decrease the cell resistance to injuries, leading to cellular apoptosis processes. Therefore, L-glutamine supplementation either in free form or as dipeptide has been investigated. Some biochemical and metabolic aspects, molecular mechanism of glutamine, as well as the effects of its supplementation are approached in the present article.Keywords: glutamine, exercise, HSP, supplementation, dipeptide. intRodUÇÃoEm 1873, Hlasiwetz e Habermann foram os primeiros a considerar a glutamina como sendo uma molécula com propriedades biologicamente importantes. Posteriormente, novas observações levaram os pesquisadores a pensar que a amônia encontrada...

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Presence of age-associated low-grade inflammation does not worsen the body response to bacterial infection in old male rats

et al. 2010

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In the field of frailty, there is an underlying hypothesis that chronic low-grade inflammation contributes to bad outcomes in response to a stressor. The host response to an Escherichia coli infection was assessed in 24 month old male rats exhibiting a chronic low-grade inflammation and in non-inflamed control rats. Mortality, weight loss and sarcopenia were the main outcomes measured. The presence of chronic low-grade inflammation did not affect post-infection mortality, body weight loss and tissue mass decreases. Infection-induced modifications of plasma acute phase proteins concentrations were not higher in low-grade inflamed than non-inflamed rats. Absolute synthesis rates of tissue proteins were independent of the initial inflammatory status, except for liver 10 days after infection. Altogether, age-associated chronic low-grade inflammation in male rats did not worsen the body response to bacterial infection. These results suggest that chronic low-grade inflammation is not an aggravating factor of the spiraling process leading to frailty.

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Alterations in glutamine synthetase activity in rat skeletal muscle are associated with advanced age

Cited by 22 publications

References 32 publications

Glutamine metabolism in advanced age

Glutamine metabolism in advanced age

Glutamina: aspectos bioquímicos, metabólicos, moleculares e suplementação

Presence of age-associated low-grade inflammation does not worsen the body response to bacterial infection in old male rats

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