Journal article
Ageing reduces the compensatory vasodilatation during hypoxic exercise: the role of nitric oxide
The Journal of physiology, Vol.589(Pt 6), pp.1477-1488
03/15/2011
DOI: 10.1113/jphysiol.2010.203539
PMCID: PMC3082105
PMID: 21282292
Abstract
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.
Details
- Title: Subtitle
- Ageing reduces the compensatory vasodilatation during hypoxic exercise: the role of nitric oxide
- Creators
- Darren P Casey - Department of Anesthesiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA. casey.darren@mayo.eduBranton G WalkerTimothy B CurryMichael J Joyner
- Resource Type
- Journal article
- Publication Details
- The Journal of physiology, Vol.589(Pt 6), pp.1477-1488
- Publisher
- England
- DOI
- 10.1113/jphysiol.2010.203539
- PMID
- 21282292
- PMCID
- PMC3082105
- ISSN
- 0022-3751
- eISSN
- 1469-7793
- Grant note
- UL1 RR024150 / NCRR NIH HHS HL-46493 / NHLBI NIH HHS R01 HL046493 / NHLBI NIH HHS AR-55819 / NIAMS NIH HHS RR-024150 / NCRR NIH HHS F32 AR055819 / NIAMS NIH HHS
- Language
- English
- Date published
- 03/15/2011
- Academic Unit
- Physical Therapy and Rehabilitation Science; Fraternal Order of Eagles Diabetes Research Center
- Record Identifier
- 9984047777902771
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