Document Detail


Lifelong physical activity prevents an age-related reduction in arterial and skeletal muscle nitric oxide bioavailability in humans.
MedLine Citation:
PMID:  22890714     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Ageing has been proposed to be associated with increased levels of reactive oxygen species (ROS) that scavenge nitric oxide (NO). In eight young sedentary (23 ± 1 years; Y), eight older lifelong sedentary (66 ± 2 years; OS) and eight older lifelong physically active subjects (62 ± 2 years; OA), we studied the effect of ROS on systemic and skeletal muscle NO bioavailability and leg blood flow by infusion of the antioxidant N-acetylcysteine (NAC). Infusion of NAC increased the bioavailability of NO in OS, as evidenced by an increased concentration of stable metabolites of NO (NOx) in the arterial and venous circulation and in the muscle interstitium. In OA, infusion of NAC only increased NOx concentrations in venous plasma whereas in Y, infusion of NAC did not affect NOx concentrations. Skeletal muscle protein levels of endothelial and neuronal NO synthase were 32% and 24% higher, respectively, in OA than in OS. Exercise at 12 W elicited a lower leg blood flow response that was associated with a lower leg oxygen uptake in OS than in Y. The improved bioavailability of NO in OS did not increase blood flow during exercise. These data demonstrate that NO bioavailability is compromised in the systemic circulation and in the musculature of sedentary ageing humans due to increased oxidative stress. Lifelong physical activity opposes this effect within the trained musculature and in the arterial circulation. The lower blood flow response to leg exercise in ageing humans is not associated with a reduced NO bioavailability.
Authors:
Michael Nyberg; James R Blackwell; Rasmus Damsgaard; Andrew M Jones; Ylva Hellsten; Stefan P Mortensen
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Publication Detail:
Type:  Controlled Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't     Date:  2012-08-13
Journal Detail:
Title:  The Journal of physiology     Volume:  590     ISSN:  1469-7793     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  2012 Nov 
Date Detail:
Created Date:  2012-11-02     Completed Date:  2013-03-25     Revised Date:  2013-11-05    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  5361-70     Citation Subset:  IM    
Affiliation:
Department of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark. mnyberg@ifi.ku.dk
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MeSH Terms
Descriptor/Qualifier:
Acetylcholine / pharmacology
Acetylcysteine / pharmacology
Adult
Aged
Aging / physiology*
Antioxidants / pharmacology
Femoral Artery / physiology*
Humans
Leg / blood supply
Male
Middle Aged
Motor Activity / physiology*
Muscle, Skeletal / physiology*
Nitrates / metabolism
Nitric Oxide / physiology*
Nitric Oxide Synthase Type I / metabolism
Nitric Oxide Synthase Type III / metabolism
Nitrites / metabolism
Norepinephrine / metabolism
Regional Blood Flow
Young Adult
Chemical
Reg. No./Substance:
0/Antioxidants; 0/Nitrates; 0/Nitrites; 10102-43-9/Nitric Oxide; 51-41-2/Norepinephrine; 51-84-3/Acetylcholine; 616-91-1/Acetylcysteine; EC 1.14.13.39/NOS3 protein, human; EC 1.14.13.39/Nitric Oxide Synthase Type I; EC 1.14.13.39/Nitric Oxide Synthase Type III
Comments/Corrections
Comment In:
J Physiol. 2012 Nov 1;590(Pt 21):5265-6   [PMID:  23118064 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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