Nutritionally essential amino acids and metabolic signaling in aging

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

Aging is associated with a gradual decline in skeletal muscle mass and strength leading to increased risk for functional impairments. Although basal rates of protein synthesis and degradation are largely unaffected with age, the sensitivity of older muscle cells to the anabolic actions of essential amino acids appears to decline. The major pathway through which essential amino acids induce anabolic responses involves the mammalian target of rapamycin (mTOR) Complex 1, a signaling pathway that is especially sensitive to regulation by the branched chain amino acid leucine. Recent evidence suggests that muscle of older individuals require increasing concentrations of leucine to maintain robust anabolic responses through the mTOR pathway. While the exact mechanisms for the age-related alterations in nutritional signaling through the mTOR pathway remain elusive, there is increasing evidence that decreased sensitivity to insulin action, reductions in endothelial function, and increased oxidative stress may be underlying factors in this decrease in anabolic sensitivity. Ensuring adequate nutrition, including sources of high quality protein, and promoting regular physical activity will remain among the frontline defenses against the onset of sarcopenia in older individuals.

Original languageEnglish (US)
Pages (from-to)431-441
Number of pages11
JournalAmino Acids
Volume45
Issue number3
DOIs
StatePublished - Sep 2013

Fingerprint

Essential Amino Acids
Sirolimus
Leucine
Muscle
Aging of materials
Sarcopenia
Branched Chain Amino Acids
Muscle Strength
Muscle Cells
Proteolysis
Insulin Resistance
Skeletal Muscle
Oxidative Stress
Oxidative stress
Nutrition
Muscles
Proteins
Cells
Insulin
Degradation

Keywords

  • Anabolic resistance
  • Protein synthesis
  • Skeletal muscle

ASJC Scopus subject areas

  • Biochemistry
  • Clinical Biochemistry
  • Organic Chemistry

Cite this

Nutritionally essential amino acids and metabolic signaling in aging. / Dillon, Edgar.

In: Amino Acids, Vol. 45, No. 3, 09.2013, p. 431-441.

Research output: Contribution to journalArticle

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