Document Detail

No major sex differences in muscle protein synthesis rates in the postabsorptive state and during hyperinsulinemia-hyperaminoacidemia in middle-aged adults.
MedLine Citation:
PMID:  19644030     Owner:  NLM     Status:  MEDLINE    
Men have more muscle than women, but most studies evaluating sex differences in muscle protein metabolism have been unable to discern sexual dimorphism in basal muscle protein turnover rates in young and middle-aged adults. We hypothesized that the anabolic response to nutritional stimuli (i.e., amino acids and insulin) would be greater in young/middle-aged men than women. We therefore measured the rates of muscle protein synthesis (MPS) in 16 healthy individuals [8 men and 8 women, matched for age (mean +/- SE: 37.7 +/- 1.5 yr) and body mass index (25.2 +/- 0.7 kg/m2)] after an overnight fast (plasma insulin approximately 5 microU/ml and plasma phenylalanine approximately 60 microM) and during a hyperinsulinemic-hyperaminoacidemic-euglycemic clamp (plasma insulin approximately 28 microU/ml; plasma phenylalanine approximately 110 microM; plasma glucose approximately 5.4 mM). The rates of MPS were not different between men and women (ANOVA main effect for sex; P = 0.49). During the clamp, the rate of MPS increased by approximately 50% (P = 0.003) with no difference in the increases from basal values between men and women (+0.019 +/- 0.004 vs. +0.018 +/- 0.010%/h, respectively; P = 0.93). There were also no differences between men and women in the basal concentrations of muscle phosphorylated Akt(Ser473), Akt(Thr308), mTOR(Ser2448), and p70s6k(Thr389) or in the hyperinsulinemia-hyperaminoacidemia-induced increases in phosphorylation of those signaling elements (P > or = 0.25). We conclude that there are no major differences in the rate of MPS and its intracellular control during basal conditions and during hyperinsulinemia-hyperaminoacidema between young and middle-aged adult men and women.
Gordon I Smith; Philip Atherton; Dominic N Reeds; B Selma Mohammed; Hadia Jaffery; Debbie Rankin; Michael J Rennie; Bettina Mittendorfer
Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2009-07-30
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  107     ISSN:  1522-1601     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2009 Oct 
Date Detail:
Created Date:  2009-10-16     Completed Date:  2009-12-24     Revised Date:  2014-09-08    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1308-15     Citation Subset:  IM    
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MeSH Terms
Blood Glucose / metabolism
Body Composition
Glucose Clamp Technique
Hyperinsulinism / genetics,  metabolism*
Infusions, Intravenous
Insulin / administration & dosage,  blood,  metabolism*
Leucine / blood
Muscle Proteins / biosynthesis*,  genetics
Muscle, Skeletal / metabolism*
Phenylalanine / administration & dosage,  blood,  metabolism*
Protein Kinases / metabolism
Proto-Oncogene Proteins c-akt / metabolism
RNA / biosynthesis
Ribosomal Protein S6 Kinases, 70-kDa / metabolism
Sex Factors
Signal Transduction
TOR Serine-Threonine Kinases
Grant Support
AR-49869/AR/NIAMS NIH HHS; BB/C516779/1//Biotechnology and Biological Sciences Research Council; BB/XX510697/1//Biotechnology and Biological Sciences Research Council; DK-56341/DK/NIDDK NIH HHS; P30 DK056341/DK/NIDDK NIH HHS; P30 DK056341-08/DK/NIDDK NIH HHS; P30 DK056341-09/DK/NIDDK NIH HHS; RR-00954/RR/NCRR NIH HHS; UL1 TR000448/TR/NCATS NIH HHS; UL1-RR-024992/RR/NCRR NIH HHS
Reg. No./Substance:
0/Blood Glucose; 0/Insulin; 0/Muscle Proteins; 47E5O17Y3R/Phenylalanine; 63231-63-0/RNA; EC 2.7.-/Protein Kinases; EC protein, human; EC Serine-Threonine Kinases; EC Proteins c-akt; EC Protein S6 Kinases, 70-kDa; GMW67QNF9C/Leucine

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