Lactate and epinephrine during exercise in altitude natives
| Autor: | Hilde Spielvogel, B. Sempore, Guido Ferretti, H. Koubi, Roland Favier, Dominique Desplanches, Bengt Kayser, Hans Hoppeler |
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| Jazyk: | angličtina |
| Rok vydání: | 1996 |
| Předmět: |
Adult
Exercise/ physiology Male medicine.medical_specialty Epinephrine Physiology Lactates/ metabolism Physical exercise Incremental exercise Altitude Physiology (medical) Internal medicine parasitic diseases medicine Humans Power output Exercise physiology Exercise Chemistry Effects of high altitude on humans ddc:616.8 Endocrinology Lactates Catecholamine Epinephrine/ metabolism medicine.drug |
| Zdroj: | Journal of Applied Physiology: Respiratory, Environmental & Exercise Physiology, Vol. 81, No 6 (1996) pp. 2488-2494 Europe PubMed Central |
| ISSN: | 0161-7567 |
| Popis: | Kayser, Bengt, Roland Favier, Guido Ferretti, Dominique Desplanches, Hilde Spielvogel, Harry Koubi, Brigitte Sempore, and Hans Hoppeler. Lactate and epinephrine during exercise in altitude natives. J. Appl. Physiol. 81(6): 2488–2494, 1996.—We tested the hypothesis that the reported low blood lactate accumulation ([La]) during exercise in altitude-native humans is refractory to hypoxia-normoxia transitions by investigating whether acute changes in inspired O2 fraction ([Formula: see text]) affect the [La] vs. power output (W˙) relationship or, alternatively, as reported for lowlanders, whether changes in [La] vs. W˙ on changes in[Formula: see text] 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 (V˙o 2) vs.W˙ relationships were not altered by[Formula: see text]. AN increased two-leg peak V˙o 2 by 10% and peakW˙ by 7%. AN paradoxically decreased one-leg peak V˙o 2 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[Formula: see text]. 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[Formula: see text] on [La] during exercise. |
| Databáze: | OpenAIRE |
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