Control and sensation of breathing during cycling exercise in hypoxia under naloxone: a randomised controlled crossover trial.

Détails

ID Serval
serval:BIB_017659320954
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Control and sensation of breathing during cycling exercise in hypoxia under naloxone: a randomised controlled crossover trial.
Périodique
Extreme Physiology and Medicine
Auteur(s)
Koglin L., Kayser B.
ISSN
2046-7648 (Electronic)
ISSN-L
2046-7648
Statut éditorial
Publié
Date de publication
2013
Volume
2
Numéro
1
Pages
1
Langue
anglais
Résumé
BACKGROUND: Opioid receptors are possibly involved in the perception of exertion and the ventilatory response to exercise. We compared incremental cycling exercise in conditions of normoxia and hypoxia (11% O2) after injection of the opioid receptor antagonist naloxone (30 mg i.v.) or placebo. Naloxone was expected to increase sensation of breathing and cycling and to curtail exercise performance more in hypoxia.
METHODS: Ten healthy subjects (29 ± 2 years, 183 ± 6 cm, 75 ± 7 kg, mean ± SD) cycled in normoxia and hypoxia until voluntary exhaustion, receiving naloxone or placebo in a balanced double-blind crossover design.
RESULTS: Hypoxia decreased peak power output by 37%-39% with placebo and naloxone (P < 0.001, no effect of naloxone). Switching to normoxia at exhaustion in hypoxia allowed continuing up to 97%-100% of power developed in normoxia with placebo and naloxone (P < 0.001, no effect of naloxone). Perceived exertion increased in hypoxia, dropped upon switching to normoxia and increased again towards exhaustion, no effect of naloxone. SpO2 (earlobe oximetry) was lower in hypoxia, dropping to 64%-68% with naloxone and placebo. The ventilatory response to exercise in normoxia and hypoxia was not changed by naloxone.
CONCLUSIONS: It follows that in healthy subjects the ventilatory response and the perception of exertion in hypoxia as compared to normoxia do not involve the endogenous opioid system, and the latter does not play a role in limiting maximum exercise capacity in hypoxia.
Pubmed
Open Access
Oui
Création de la notice
25/09/2013 12:46
Dernière modification de la notice
20/08/2019 13:23
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