Regulation of perfusive O2 transport during exercise in humans: effects of changes in haemoglobin concentration.

Details

Serval ID
serval:BIB_CE2FDE60AF51
Type
Article: article from journal or magazin.
Collection
Publications
Title
Regulation of perfusive O2 transport during exercise in humans: effects of changes in haemoglobin concentration.
Journal
Journal of Physiology
Author(s)
Ferretti G., Kayser B., Schena F., Turner D.L., Hoppeler H.
ISSN
0022-3751 (Print)
ISSN-L
0022-3751
Publication state
Published
Issued date
1992
Volume
455
Pages
679-688
Language
english
Abstract
1. Recently it was suggested that submaximal cardiac output (Q) could vary in response to changes in arterial O2 concentration (Ca,O2), so that arterial O2 delivery (Qa,O2 = Q x Ca,O2, in ml min-1) is kept constant. 2. This hypothesis was tested on eight healthy male subjects, at rest and during exercise (50, 100 and 150 W) in three conditions: normaemia (N), after 6 weeks of endurance training (T), and 2 days after subsequent autologous blood reinfusion (P). 3. Measured variables were oxygen consumption (VO2), by open circuit method, Q, by a CO2 rebreathing method, and haemoglobin concentration ([Hb]), by a photometric method. Ca,O2 was calculated as the product of [Hb], arterial O2 saturation (0.97), and the O2 binding coefficient. 4. [Hb] and thus Ca,O2 increased by 2.6% (T vs. N) and subsequently by further 5.8% (P vs. T). VO2 and Qa,O2 were linear functions of power (w), both relationships being unaffected by changes in Ca,O2. As a consequence, the linear Q vs. VO2 relationships were shifted downward as Ca,O2 increased. 5. The VO2 vs. w and the Qa,O2 vs. w relationships had the same slope. Therefore, the difference between Qa,O2 (w) and VO2 (w), equal to O2 flow in mixed venous blood (Qv,O2), was constant. 6. In conclusion, the tested hypothesis was supported by the present results. The observed constancy of Qv,O2 suggested that Qv,O2 may play a key role in regulating the cardiovascular response to exercise.
Keywords
Adult, Cardiac Output/physiology, Exercise/physiology, Hemoglobins/analysis, Humans, Male, Oxygen/blood, Oxygen/physiology, Oxygen Consumption/physiology
Pubmed
Web of science
Create date
25/09/2013 12:01
Last modification date
20/08/2019 15:48
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