Imperial College London
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DrJamesMoss

Faculty of Medicine, National Heart & Lung Institute

Principal Teaching Fellow
 
 
 
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Contact

 

james.moss

 
 
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Location

 

G02 Faculty Education OfficeSir Alexander Fleming BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Tew:2011:10.1152/japplphysiol.01423.2010,
author = {Tew, GA and Saxton, JM and Klonizakis, M and Moss, J and Ruddock, AD and Hodges, GJ},
doi = {10.1152/japplphysiol.01423.2010},
journal = {Journal of Applied Physiology},
pages = {1264--1270},
title = {Aging and aerobic fitness affect the contribution of noradrenergic sympathetic nerves to the rapid cutaneous vasodilator response to local heating},
url = {http://dx.doi.org/10.1152/japplphysiol.01423.2010},
volume = {110},
year = {2011}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - <jats:p> Sedentary aging results in a diminished rapid cutaneous vasodilator response to local heating. We investigated whether this diminished response was due to altered contributions of noradrenergic sympathetic nerves by assessing 1) the age-related decline and 2) the effect of aerobic fitness. Using laser-Doppler flowmetry, we measured skin blood flow (SkBF) in young (24 ± 1 yr) and older (64 ± 1 yr) endurance-trained and sedentary men ( n = 7 per group) at baseline and during 35 min of local skin heating to 42°C at 1) untreated forearm sites, 2) forearm sites treated with bretylium tosylate (BT), which prevents neurotransmitter release from noradrenergic sympathetic nerves, and 3) forearm sites treated with yohimbine + propranolol (YP), which antagonizes α- and β-adrenergic receptors. SkBF was converted to cutaneous vascular conductance (CVC = SkBF/mean arterial pressure) and normalized to maximal CVC (%CVC<jats:sub>max</jats:sub>) achieved by skin heating to 44°C. Pharmacological agents were administered using microdialysis. In the young trained group, the rapid vasodilator response was reduced at BT and YP sites ( P < 0.05); by contrast, in the young sedentary and older trained groups, YP had no effect ( P > 0.05), but BT did ( P > 0.05). Neither BT nor YP affected the rapid vasodilator response in the older sedentary group ( P > 0.05). These data suggest that the age-related reduction in the rapid vasodilator response is due to an impairment of sympathetic-dependent mechanisms, which can be partly attenuated with habitual aerobic exercise. Rapid vasodilation involves noradrenergic neurotransmitters in young trained men and nonadrenergic sympathetic cotransmitters (e.g., neuropeptide Y) in young sedentary and older trained men, possibly as a compensatory mechanism. Finally, in older sedentary men, the rapid vasodilation appears not to involve the sympathetic system. </jats:p>
AU  - Tew,GA
AU  - Saxton,JM
AU  - Klonizakis,M
AU  - Moss,J
AU  - Ruddock,AD
AU  - Hodges,GJ
DO  - 10.1152/japplphysiol.01423.2010
EP  - 1270
PY  - 2011///
SN  - 8750-7587
SP  - 1264
TI  - Aging and aerobic fitness affect the contribution of noradrenergic sympathetic nerves to the rapid cutaneous vasodilator response to local heating
T2  - Journal of Applied Physiology
UR  - http://dx.doi.org/10.1152/japplphysiol.01423.2010
VL  - 110
ER  -
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