Lactate and epinephrine during exercise in altitude natives.

Détails

ID Serval
serval:BIB_3A8AE89FF2EF
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Lactate and epinephrine during exercise in altitude natives.
Périodique
Journal of Applied Physiology
Auteur(s)
Kayser B., Favier R., Ferretti G., Desplanches D., Spielvogel H., Koubi H., Sempore B., Hoppeler H.
ISSN
8750-7587 (Print)
ISSN-L
0161-7567
Statut éditorial
Publié
Date de publication
1996
Volume
81
Numéro
6
Pages
2488-2494
Langue
anglais
Résumé
We tested the hypothesis that the reported low blood lactate accumulation ([La]) during exercise in altitude-native humans is refractory to hypoxianormoxia transitions by investigating whether acute changes in inspired O2 fraction (FIo2) affect the [La] vs. power output (W) relationship or, alternatively, as reported for lowlanders, whether changes in [La] vs. W on changes in FIo2 are related to changes in blood epinephrine concentration ([Epi]). Altitude natives [n = 8, age 24 +/- 1 (SE) yr, body mass 62 +/- 3 kg, height 167 +/- 2 cm] in La Paz, Bolivia (3,600 m) performed incremental exercise with two legs and one leg in chronic hypoxia and acute normoxia (AN). Submaximal one- and two-leg O2 uptake (Vo2) vs. W relationships were not altered by FIo2. AN increased two-leg peak Vo2 by 10% and peak W by 7%. AN paradoxically decreased one-leg peak Vo2 by 7%, whereas peak W remained the same. The [La] vs. W relationships were similar to those reported in unacclimatized lowlanders. There was a shift to the right on AN, and maximum [La] was reduced by 7 and 8% for one- and two-leg exercises, respectively. [Epi] and [La] were tightly related (mean r = 0.81) independently of FIo2. Thus normoxia attenuated the increment in both [La] and [Epi] as a function of W, whereas the correlation between [La] and [Epi] was unaffected. These data suggest loose linkage of glycolysis to oxidative phosphorylation under influence from [Epi]. In conclusion, high-altitude natives appear to be not fundamentally different from lowlanders with regard to the effect of acute changes in FIo2 on [La] during exercise.
Mots-clé
Adult, Altitude, Epinephrine/metabolism, Exercise/physiology, Humans, Lactates/metabolism, Male
Pubmed
Web of science
Création de la notice
19/09/2013 11:00
Dernière modification de la notice
20/08/2019 14:30
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