| Ageing reduces the compensatory vasodilatation during hypoxic exercise: the role of nitric oxide. | |
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MedLine Citation:
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PMID: 21282292 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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We tested the hypotheses that (1) the compensatory vasodilatation in skeletal muscle during hypoxic exercise is attenuated in ageing humans and (2) local inhibition of nitric oxide (NO) synthesis in the forearm of ageing humans will have less impact on the compensatory dilatation during rhythmic exercise with hypoxia, due to a smaller compensatory dilator response. Eleven healthy older subjects (61 ± 2 years) performed forearm exercise (10% and 20% of maximum) during saline infusion (control) and NO synthase inhibition (NG-monomethyl-L-arginine; L-NMMA) under normoxic and normocapnic hypoxic (80% arterial O2 saturation) conditions. Forearm vascular conductance (FVC; ml min⁻¹ (100 mmHg)⁻¹) was calculated from forearm blood flow(ml min⁻¹) and blood pressure (mmHg). To further examine the effects of ageing on the compensatory vasodilator response to hypoxic exercise we compared the difference in ΔFVC (% change compared to respective normoxic exercise trial) between the older subjects (present study) and previously published data from an identical protocol in young subjects. During the control condition, the compensatory vasodilator response to hypoxia was similar between the old and young groups at 10% exercise (28 ± 6% vs. 40 ± 8%, P =0.11) but attenuated at 20% exercise (14 ± 4% vs. 31 ± 6%, P <0.05). L-NMMA during hypoxic exercise only blunted the compensatory vasodilator response in the young group (P <0.05). Our data suggest that ageing reduces the compensatory vasodilator response to hypoxic exercise via blunted NO signalling. |
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Authors:
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Darren P Casey; Branton G Walker; Timothy B Curry; Michael J Joyner |
Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2011-01-31 |
Journal Detail:
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Title: The Journal of physiology Volume: 589 ISSN: 1469-7793 ISO Abbreviation: J. Physiol. (Lond.) Publication Date: 2011 Mar |
Date Detail:
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Created Date: 2011-04-13 Completed Date: 2012-03-06 Revised Date: 2012-03-15 |
Medline Journal Info:
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Nlm Unique ID: 0266262 Medline TA: J Physiol Country: England |
Other Details:
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Languages: eng Pagination: 1477-88 Citation Subset: IM |
Affiliation:
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Department of Anesthesiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA. casey.darren@mayo.edu |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adaptation, Physiological
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physiology Aged Aging / physiology* Anoxia / physiopathology* Exercise / physiology* Female Hemodynamics / physiology Humans Male Middle Aged Nitric Oxide / physiology* Vasodilation / physiology* |
| Grant Support | |
ID/Acronym/Agency:
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AR-55819/AR/NIAMS NIH HHS; HL-46493/HL/NHLBI NIH HHS; RR-024150/RR/NCRR NIH HHS |
| Chemical | |
Reg. No./Substance:
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10102-43-9/Nitric Oxide |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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