Linked Life Data

11134097

Source:http://linkedlifedata.com/resource/pubmed/id/11134097

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2001-2-2
pubmed:abstractText
Muscle mass declines with aging. Amino acids alone stimulate muscle protein synthesis in the elderly. However, mixed nutritional supplementation failed to improve muscle mass. We hypothesized that the failure of nutritional supplements is due to altered responsiveness of muscle protein anabolism to increased amino acid availability associated with endogenous hyperinsulinemia. We measured muscle protein synthesis and breakdown, and amino acid transport in healthy young (30 +/- 3 yr) and elderly (72 +/- 1 yr) volunteers in the basal postabsorptive state and during the administration of an amino acid-glucose mixture, using L-[ring-(2)H(5)]phenylalanine infusion, femoral artery and vein catheterization, and muscle biopsies. Basal muscle amino acid turnover was similar in young and elderly subjects. The mixture increased phenylalanine leg delivery and transport into the muscle in both groups. Phenylalanine net balance increased in both groups (young, -27 +/- 8 to 64 +/- 17; elderly, -16 +/- 4 to 29 +/- 7 nmol/(min.100 mL); P: < 0.0001, basal vs. mixture), but the increase was significantly blunted in the elderly (P: = 0.030 vs. young). Muscle protein synthesis increased in the young, but remained unchanged in the elderly [young, 61 +/- 17 to 133 +/- 30 (P: = 0. 005); elderly, 62 +/- 9 to 70 +/- 14 nmol/(min.100 mL) (P: = NS)]. In both groups, protein breakdown decreased (P: = 0.012) and leg glucose uptake increased (P: = 0.0258) with the mixture. We conclude that the response of muscle protein anabolism to hyperaminoacidemia with endogenous hyperinsulinemia is impaired in healthy elderly due to the unresponsiveness of protein synthesis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-972X
pubmed:author
pubmed:issnType
Print
pubmed:volume
85
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4481-90
pubmed:dateRevised
2011-10-13
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
The response of muscle protein anabolism to combined hyperaminoacidemia and glucose-induced hyperinsulinemia is impaired in the elderly.
pubmed:affiliation
Departments of Internal Medicine, University of Texas Medical Branch, Galveston, Texas 77550, USA.
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't