Oxidative-nitrosative stress and systemic vascular function in highlanders with and without exaggerated hypoxemia.

Détails

ID Serval
serval:BIB_6C3787562448
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Oxidative-nitrosative stress and systemic vascular function in highlanders with and without exaggerated hypoxemia.
Périodique
Chest
Auteur⸱e⸱s
Bailey D.M., Rimoldi S.F., Rexhaj E., Pratali L., Salinas Salmòn C., Villena M., McEneny J., Young I.S., Nicod P., Allemann Y., Scherrer U., Sartori C.
ISSN
1931-3543 (Electronic)
ISSN-L
0012-3692
Statut éditorial
Publié
Date de publication
2013
Peer-reviewed
Oui
Volume
143
Numéro
2
Pages
444-451
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Résumé
BACKGROUND: Acute exposure to high altitude stimulates free radical formation in lowlanders, yet whether this persists during chronic exposure in healthy, well-adapted and maladapted highlanders suffering from chronic mountain sickness (CMS) remains to be established.
METHODS: Oxidative-nitrosative stress (as determined by the presence of the biomarkers ascorbate radical [A •- ], via electron paramagnetic resonance spectroscopy, and nitrite [NO 2 2 ], via ozone-based chemiluminescence) was assessed in venous blood of 25 male highlanders in Bolivia living at 3,600 m with CMS (n 5 13, CMS 1 ) and without CMS (n 5 12, CMS 2 ). Twelve age- and activity-matched, healthy, male lowlanders were examined at sea level and during acute hypoxia. We also measured fl ow-mediated dilatation (FMD), arterial stiffness defined by augmentation index normalized for a heart rate of 75 beats/min (AIx-75), and carotid intima-media thickness (IMT).
RESULTS: Compared with normoxic lowlanders, oxidative-nitrosative stress was moderately increased in the CMS 2 group ( P , .05), as indicated by elevated A •- (3,191 457 arbitrary units [AU] vs 2,640 445 AU) and lower NO 2 2 (206 55 nM vs 420 128 nM), whereas vascular function remained preserved. This was comparable to that observed during acute hypoxia in lowlanders in whom vascular dysfunction is typically observed. In contrast, this response was markedly exaggerated in CMS 1 group (A •- , 3,765 429 AU; NO 2 2 , 148 50 nM) compared with both the CMS 2 group and lowlanders ( P , .05). This was associated with systemic vascular dysfunction as indicated by lower ( P , .05 vs CMS 2 ) FMD (4.2% 0.7% vs 7.6% 1.7%) and increased AIx-75 (23% 8% vs 12% 7%) and carotid IMT (714 127 m M vs 588 94 m M).
CONCLUSIONS: Healthy highlanders display a moderate, sustained elevation in oxidative-nitrosative stress that, unlike the equivalent increase evoked by acute hypoxia in healthy lowlanders, failed to affect vascular function. Its more marked elevation in patients with CMS may contribute to systemic vascular dysfunction.
Mots-clé
Adaptation, Physiological/physiology, Altitude, Altitude Sickness/metabolism, Altitude Sickness/physiopathology, Anoxia/metabolism, Anoxia/physiopathology, Antioxidants/metabolism, Bolivia, Cardiovascular System/physiopathology, Carotid Intima-Media Thickness, Case-Control Studies, Free Radicals/metabolism, Heart Rate/physiology, Humans, Male, Middle Aged, Nitric Oxide/metabolism, Nitrosation/physiology, Oxidative Stress/physiology
Pubmed
Web of science
Création de la notice
22/01/2013 15:20
Dernière modification de la notice
20/08/2019 14:26
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