Document Detail

Hyperbaric hyperoxia reduces exercising forearm blood flow in humans.
MedLine Citation:
PMID:  21421819     Owner:  NLM     Status:  MEDLINE    
Hypoxia during exercise augments blood flow in active muscles to maintain the delivery of O(2) at normoxic levels. However, the impact of hyperoxia on skeletal muscle blood flow during exercise is not completely understood. Therefore, we tested the hypothesis that the hyperemic response to forearm exercise during hyperbaric hyperoxia would be blunted compared with exercise during normoxia. Seven subjects (6 men/1 woman; 25 ± 1 yr) performed forearm exercise (20% of maximum) under normoxic and hyperoxic conditions. Forearm blood flow (FBF; in ml/min) was measured using Doppler ultrasound. Forearm vascular conductance (FVC; in ml·min(-1)·100 mmHg(-1)) was calculated from FBF and blood pressure (in mmHg; brachial arterial catheter). Studies were performed in a hyperbaric chamber with the subjects supine at 1 atmospheres absolute (ATA) (sea level) while breathing normoxic gas [21% O(2), 1 ATA; inspired Po(2) (Pi(O(2))) ≈ 150 mmHg] and at 2.82 ATA while breathing hyperbaric normoxic (7.4% O(2), 2.82 ATA, Pi(O(2)) ≈ 150 mmHg) and hyperoxic (100% O(2), 2.82 ATA, Pi(O(2)) ≈ 2,100 mmHg) gas. Resting FBF and FVC were less during hyperbaric hyperoxia compared with hyperbaric normoxia (P < 0.05). The change in FBF and FVC (Δ from rest) during exercise under normoxia (204 ± 29 ml/min and 229 ± 37 ml·min(-1)·100 mmHg(-1), respectively) and hyperbaric normoxia (203 ± 28 ml/min and 217 ± 35 ml·min(-1)·100 mmHg(-1), respectively) did not differ (P = 0.66-0.99). However, the ΔFBF (166 ± 21 ml/min) and ΔFVC (163 ± 23 ml·min(-1)·100 mmHg(-1)) during hyperbaric hyperoxia were substantially attenuated compared with other conditions (P < 0.01). Our data suggest that exercise hyperemia in skeletal muscle is highly dependent on oxygen availability during hyperoxia.
Darren P Casey; Michael J Joyner; Paul L Claus; Timothy B Curry
Related Documents :
8983919 - Blood lactate and pyruvate concentrations, and their ratio during exercise in healthy c...
4003569 - Energy sources in fully aerobic rest-work transitions: a new role for glycolysis.
9839389 - Continuous measurement of subcutaneous lactate concentration during exercise by combini...
3221439 - Effect of nifedipine, dilazep, dinitrates and propranolol on blood lactate accumulation...
16772579 - The effect of digit amputation or arthrodesis surgery on culling and milk production in...
18379209 - Current trends in lactate metabolism: introduction.
1310299 - Results of the intercalibration study of laboratories involved in assessing the environ...
24194479 - S100b as a marker for brain damage and blood-brain barrier disruption following exercise.
24504429 - Heart rate and its variability in response to running-associations with troponin.
Publication Detail:
Type:  Comparative Study; Journal Article     Date:  2011-03-18
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  300     ISSN:  1522-1539     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2011 May 
Date Detail:
Created Date:  2011-05-02     Completed Date:  2011-07-07     Revised Date:  2013-06-30    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  H1892-7     Citation Subset:  IM    
Dept. of Anesthesiology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Blood Pressure / physiology
Exercise / physiology*
Forearm / blood supply*,  ultrasonography
Hyperbaric Oxygenation*
Hyperoxia / physiopathology*
Muscle, Skeletal / blood supply,  physiopathology
Oxygen / blood
Regional Blood Flow / physiology*
Ultrasonography, Doppler
Reg. No./Substance:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Dysfunctional ryanodine receptor and cardiac hypertrophy: role of signaling molecules.
Next Document:  Quantification of Pre-systolic Blood Flow Organization and Energetics in the Human Left Ventricle.