Journal of Applied Physiology Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 57: 1507-1511, 1984;
8750-7587/84 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Escourrou, P.
Right arrow Articles by Rowell, L. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Escourrou, P.
Right arrow Articles by Rowell, L. B.

Journal of Applied Physiology, Vol 57, Issue 5 1507-1511, Copyright © 1984 by American Physiological Society

ARTICLES

Hypoxemia increases plasma catecholamine concentrations in exercising humans

P. Escourrou, D. G. Johnson and L. B. Rowell

To determine whether plasma catecholamine concentrations (a measure of sympathetic nervous activity [SNA]) rise above normoxic levels during exercise with hypoxemia, we exercised seven men for 15 min at three loads that required from 40 to 88% of maximal O2 uptake (VO2max). Subjects breathed room air on one day and 11-12% O2 on another with relative work loads corrected for the 24% fall in VO2max during hypoxemia. Hypoxemia caused large increments in norepinephrine (NE) concentration (radioenzyme technique) to 1.21 +/- 0.20 ng/ml (mean +/- SE), 2.79 +/- 0.38, and up to 5.90 +/- 0.75 (hypoxemia) compared with 0.89 +/- 0.06, 1.66 +/- 0.16, and 3.95 +/- 0.39 in normoxia at the three loads, respectively (P less than 0.001). Epinephrine (E) concentration approximately doubled (P less than 0.001) in hypoxemia at each load when compared with normoxic levels (i.e., 0.10 +/- 0.01 ng/ml, 0.23 +/- 0.03, and 0.46 +/- 0.06 in normoxia). However, hypoxemia did not significantly alter linear relationships between log plasma NE concentration and either heart rate (HR) or percent VO2max utilized, or between HR and percent VO2max. Thus NE concentration, like HR, appeared to reflect relative severity of exercise and overall SNA in both hypoxemia and normoxia. Above 40% VO2max during hypoxemia, circulating NE and E far exceeded levels known to have direct vasoconstrictor and metabolic effects in normoxic humans, but hypoxemia may blunt vasoconstriction in some regions.


This article has been cited by other articles:


Home page
 J. Exp. Biol.Home page
T. D. Noakes, J. E. Peltonen, and H. K. Rusko
Evidence that a central governor regulates exercise performance during acute hypoxia and hyperoxia
J. Exp. Biol., March 11, 2002; 204(18): 3225 - 3234.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
R. S. Mazzeo, J. D. Carroll, Gail. E. Butterfield, B. Braun, P. B. Rock, E. E. Wolfel, S. Zamudio, and L. G. Moore
Catecholamine responses to {alpha}-adrenergic blockade during exercise in women acutely exposed to altitude
J Appl Physiol, January 1, 2001; 90(1): 121 - 126.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online