| Lactate and epinephrine during exercise in altitude natives. | |
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MedLine Citation:
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PMID: 9018496 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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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. |
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Authors:
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B Kayser; R Favier; G Ferretti; D Desplanches; H Spielvogel; H Koubi; B Sempore; H Hoppeler |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 81 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 1996 Dec |
Date Detail:
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Created Date: 1997-04-09 Completed Date: 1997-04-09 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 2488-94 Citation Subset: IM; S |
Affiliation:
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Département de Physiologie, Centre Médical Universitaire, Universität Bern, Switzerland. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adult Altitude* Epinephrine / metabolism* Exercise / physiology* Humans Lactates / metabolism* Male |
| Chemical | |
Reg. No./Substance:
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0/Lactates; 51-43-4/Epinephrine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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