Document Detail


Oxidative stress contributes to the augmented exercise pressor reflex in peripheral arterial disease patients.
MedLine Citation:
PMID:  23006479     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Exaggerated blood pressure (BP) responses to dynamic exercise predict cardiovascular mortality in patients with peripheral arterial disease (PAD). However, the underlying mechanisms are unclear and no attempt has been made to attenuate this response using antioxidants. Three physiological studies were conducted in patients with PAD and controls. In Protocol 1, subjects underwent 4 min of low-intensity (0.5-2.0 kg), rhythmic plantar flexion in the supine posture. In Protocol 2, patients with PAD received high-dose ascorbic acid intravenously before exercise. In Protocol 3, involuntary exercise was conducted via electrical stimulation of the tibial nerve. The primary outcome measure was Δ mean arterial pressure (MAP) during the first 20 s of exercise (i.e. the onset of sympathoexcitation by muscle afferents). Compared to controls, patients with PAD had significantly greater ΔMAP during plantar flexion, particularly at 0.5 kg with the most affected leg (11 ± 2 vs. 2 ± 1 mmHg) as well as the least affected leg (7 ± 1 vs. 1 ± 1 mmHg). This augmented response occurred before the onset of claudication pain and was attenuated by ∼50% with ascorbic acid. Electrically evoked exercise also elicited larger haemodynamic changes in patients with PAD compared to controls. Further, the ΔMAP during 0.5 kg plantar flexion inversely correlated with the ankle-brachial index, indicating that patients with more severe resting limb ischaemia have a larger BP response to exercise. The BP response to low-intensity exercise was enhanced in PAD. Chronic limb ischaemia may sensitize muscle afferents and potentiate the BP response to muscle contraction in a dose-dependent manner.
Authors:
Matthew D Muller; Rachel C Drew; Cheryl A Blaha; Jessica L Mast; Jian Cui; Amy B Reed; Lawrence I Sinoway
Related Documents :
22717259 - Enlarged right ventricular size at 11 years' follow-up after closure of secundum-type a...
23724749 - Can my patient with cvd travel to high altitude?
24602319 - Modulation of cardiac mitochondrial permeability transition and apoptotic signaling by ...
11903819 - Altered cytokeratin expression during chemoprevention of experimental hamster buccal po...
1175699 - Estimation of the ld1 and extrapolation of the ld0.1 for five organothiophosphate pesti...
9249559 - Serotonergic afferents mediate activity-dependent entrainment of the mouse circadian cl...
6863099 - Cardiorespiratory responses to exercise distributed between the upper and lower body.
22717259 - Enlarged right ventricular size at 11 years' follow-up after closure of secundum-type a...
17510689 - Eat, run, and...shiver? from the exercise--diet and energy balance symposium at csep 2005.
Publication Detail:
Type:  Controlled Clinical Trial; Journal Article; Research Support, N.I.H., Extramural     Date:  2012-09-24
Journal Detail:
Title:  The Journal of physiology     Volume:  590     ISSN:  1469-7793     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  2012 Dec 
Date Detail:
Created Date:  2012-12-03     Completed Date:  2013-05-17     Revised Date:  2013-12-04    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  6237-46     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Aged
Antioxidants / pharmacology
Ascorbic Acid / pharmacology
Blood Pressure / physiology*
Electric Stimulation
Exercise / physiology*
Female
Heart Rate / physiology
Humans
Male
Middle Aged
Oxidative Stress / physiology*
Peripheral Arterial Disease / physiopathology*
Reflex / physiology
Tibial Nerve / physiology
Grant Support
ID/Acronym/Agency:
C06 RR016499/RR/NCRR NIH HHS; P01 HL096570/HL/NHLBI NIH HHS; P01 HL096570/HL/NHLBI NIH HHS; UL1 RR033184/RR/NCRR NIH HHS; UL1 TR000127/TR/NCATS NIH HHS
Chemical
Reg. No./Substance:
0/Antioxidants; PQ6CK8PD0R/Ascorbic Acid
Comments/Corrections
Comment In:
J Physiol. 2012 Dec 1;590(Pt 23):5933-4   [PMID:  23204101 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Features of proximal and distal excitatory synaptic inputs to layer V neurons of the rat medial ento...
Next Document:  Dihydropyridine receptors actively control gating of ryanodine receptors in resting mouse skeletal m...