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Impact of age and body position on the contribution of nitric oxide to femoral artery shear rate: implications for atherosclerosis (1079.21)
Author(s) -
Trinity Joel,
Groot H.,
Layec Gwenael,
Rossman Matthew,
Ives Stephen,
Richardson Russell
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.1079.21
Subject(s) - supine position , medicine , femoral artery , cardiology , shear rate , shear (geology) , artery , materials science , viscosity , composite material
Age‐related alterations in shear rate in humans have only been examined in the atherosclerotic‐resistant conduit vessels of the arm. This study sought to examine the contribution of nitric oxide (NO) to age‐related alterations in shear rate and the impact of common body positions (supine and seated) in the atherosclerotic‐prone conduit artery of the leg. Inhibition of NO synthase (NOS) was accomplished by intra‐arterial infusion of L‐NMMA and common femoral artery diameter and blood velocity were measured by Doppler ultrasound in 8 young (24±1 yr) and 8 old (75±3 yr) healthy men. Old subjects exhibited reduced mean shear rate in the supine (18.2±2.5 sec‐1) and seated positions (17.2±2.5 sec‐1) compared with young subjects (supine: 41.5±5.9 sec‐1, seated: 32.2±4.0 sec‐1). This reduced mean shear in the old was driven by attenuated antegrade shear as there were no differences in retrograde shear. NOS inhibition reduced antegrade shear in the young such that age‐related differences were abolished. In contrast, NOS‐induced reductions in retrograde shear rate were similar between groups. The seated position reduced mean shear rate in the young to that normally observed in old. Overall, this study reveals that age‐related reductions in mean shear rate, assessed in the atherosclerotic‐prone vasculature of the leg, are largely explained by reductions in antegrade shear rate as a result of reduced NO bioavailability. Grant Funding Source : Support by VA Advanced Fellowship in Geriatrics, VA Merit Award, and NIH PPG