Journal article
Impact of aging on conduit artery retrograde and oscillatory shear at rest and during exercise: Role of nitric oxide
Hypertension (Dallas, Tex. 1979), Vol.57(3), pp.484-489
03/2011
DOI: 10.1161/HYPERTENSIONAHA.110.165365
PMCID: PMC3049300
PMID: 21263118
Abstract
Aging has been recently associated with increased retrograde and oscillatory shear in peripheral conduit arteries; a hemodynamic environment that favors a pro-atherogenic endothelial cell phenotype. We evaluated whether nitric oxide (NO) bioavailability in resistance vessels contributes to age-related differences in shear rate patterns in upstream conduit arteries at rest and during rhythmic muscle contraction. Young (n=11, 26±2 yr) and older (n=11, 61±2 yr) healthy subjects received intra-arterial saline (control) and the NO synthase inhibitor
N
G
-Monomethyl-L-arginine (L-NMMA). Brachial artery diameter and velocities were measured via Doppler ultrasound at rest and during a 5-min bout of rhythmic forearm exercise. At rest, older subjects exhibited greater brachial artery retrograde and oscillatory shear (−13.2±3.0 s
−1
and 0.11±.0.02 a.u., respectively) compared to young subjects (−4.8±2.3 s
−1
and 0.04±0.02 a.u., respectively; both p<0.05). NO synthase inhibition in the forearm circulation of young, but not older, subjects increased retrograde and oscillatory shear (both p<0.05) such that differences between young and old at rest were abolished (both p>0.05). From rest to steady state exercise, older subjects decreased retrograde and oscillatory shear (both p<0.05) to the extent that no exercise-related differences were found between groups (both p>0.05). Inhibition of NO synthase in the forearm circulation did not affect retrograde and oscillatory shear during exercise in either group (all p>0.05). These data demonstrate for the first time that reduced NO bioavailability in the resistance vessels contributes, in part, to the age-related discrepancies in resting shear patterns, thus identifying a potential mechanism for increased risk of atherosclerotic disease in conduit arteries.
Details
- Title: Subtitle
- Impact of aging on conduit artery retrograde and oscillatory shear at rest and during exercise: Role of nitric oxide
- Creators
- Jaume Padilla - Biomedical Sciences, University of Missouri, Columbia, MOGrant H Simmons - Biomedical Sciences, University of Missouri, Columbia, MOPaul J Fadel - Medical Pharmacology and Physiology, University of Missouri, Columbia, MOM. Harold Laughlin - Biomedical Sciences, University of Missouri, Columbia, MOMichael J Joyner - Anesthesiology, Mayo Clinic, Rochester, MNDarren P Casey - Anesthesiology, Mayo Clinic, Rochester, MN
- Resource Type
- Journal article
- Publication Details
- Hypertension (Dallas, Tex. 1979), Vol.57(3), pp.484-489
- DOI
- 10.1161/HYPERTENSIONAHA.110.165365
- PMID
- 21263118
- PMCID
- PMC3049300
- ISSN
- 0194-911X
- eISSN
- 1524-4563
- Language
- English
- Date published
- 03/2011
- Academic Unit
- Physical Therapy and Rehabilitation Science; Fraternal Order of Eagles Diabetes Research Center
- Record Identifier
- 9984047741402771
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