| Hyperbaric hyperoxia reduces exercising forearm blood flow in humans. | |
| | |
MedLine Citation:
|
PMID: 21421819 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
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. |
| | |
Authors:
|
Darren P Casey; Michael J Joyner; Paul L Claus; Timothy B Curry |
Related Documents
:
|
3985159 - Lactate production in isolated segments of the rat nephron. 14998099 - Maximal lactate steady state in trained adolescent runners. 10776889 - Cardiorespiratory and metabolic responses to exercise in hbsc sickle cell patients. 3341469 - Follow-up study of control subjects with lactate- and isoproterenol-induced panic attacks. 19650379 - Specific circuit training in young judokas: effects of rest duration. 17286209 - The declining phase of lactation: peripheral or central, programmed or pathological? 8902309 - Effect of physical fitness on plasma lipids in young chinese adults. 17827399 - Role of low energy expenditure and sitting in obesity, metabolic syndrome, type 2 diabe... 6341339 - Time course of the bronchoconstriction induced by inhaled histamine and methacholine. |
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: 2012-05-01 |
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 |
Affiliation:
|
Dept. of Anesthesiology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905. casey.darren@mayo.edu. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adult Blood Pressure / physiology Exercise / physiology* Female Forearm / blood supply*, ultrasonography Humans Hyperbaric Oxygenation* Hyperoxia / physiopathology* Male Muscle, Skeletal / blood supply, physiopathology Oxygen / blood Regional Blood Flow / physiology* Ultrasonography, Doppler |
| Chemical | |
Reg. No./Substance:
|
7782-44-7/Oxygen |
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.