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Endothelin-1 and oxygen saturation during exercise in normoxia and hyposia Giles, Luisa

Abstract

We tested the hypothesis that decrements in arterial oxyhaemoglobin saturation could be related to elevations in circulating endothelin-1 following 30 minutes of exercise at ventilatory threshold. Eight aerobically trained males (mean ± SEM: age 26.14 ± 1.77 years, height 182.36 ± 1 . 5 1 cm, mass 72.89 ± 2.62 kg) completed 2 maximal exercise tests (mean ± SEM: normoxia (n) 68.56 ± 2.06 mL.kg-¹min-¹; hypoxia (Fi02 0.14)(h) 53.88 ± 1.35 mL.kg-¹.min-¹), and two 30-minute steady state exercise protocols at the power achieved at threshold during maximal exercise tests (mean ± SEM: power (Watts) 257.14 ± 21.57 (n) 191.25 ± 10.79 (Fi02 0.14)(h); HR (bpm) 161.7 ± 5.34 (n) 156.6 ± 3.45 (h)). When participants exercised for 30 minutes at ventilatory threshold inspiring 14%02, a significant decrease in oxygen saturation (as measured by pulse oximetry) was observed, when compared to values in normoxia (80.2 ± 1.17 % (h) vs 94.12 ± 0.24 % (n); p<0.001). This desaturation was not accompanied by significant changes in plasma endothelin-1 (ET-1), big endothelin-1 (BigET-1) or nitric oxide (NO). Both pulmonary artery pressure (PAP) and oscillatory compliance (OC) were significantly greater following exercise (F[superscript omitted] = 4.74 p< 0.05), compared to pre-exercise values. These outcome variables were not different between normoxia and hypoxia. Plasma ET-1 or BigET-1 levels did not differ significantly over time or across conditions F[superscript omitted] = 4.74 p> 0.05). In conclusion, plasma ET-1 levels following 30-minutes of steady state exercise at ventilatory threshold are unrelated to decrements in oxyhaemoglobin saturation.

Item Metadata

Title
Endothelin-1 and oxygen saturation during exercise in normoxia and hyposia
Creator
Giles, Luisa
Publisher
University of British Columbia
Date Issued
2007
Description
We tested the hypothesis that decrements in arterial oxyhaemoglobin saturation could be related to elevations in circulating endothelin-1 following 30 minutes of exercise at ventilatory threshold. Eight aerobically trained males (mean ± SEM: age 26.14 ± 1.77 years, height 182.36 ± 1 . 5 1 cm, mass 72.89 ± 2.62 kg) completed 2 maximal exercise tests (mean ± SEM: normoxia (n) 68.56 ± 2.06 mL.kg-¹min-¹; hypoxia (Fi02 0.14)(h) 53.88 ± 1.35 mL.kg-¹.min-¹), and two 30-minute steady state exercise protocols at the power achieved at threshold during maximal exercise tests (mean ± SEM: power (Watts) 257.14 ± 21.57 (n) 191.25 ± 10.79 (Fi02 0.14)(h); HR (bpm) 161.7 ± 5.34 (n) 156.6 ± 3.45 (h)). When participants exercised for 30 minutes at ventilatory threshold inspiring 14%02, a significant decrease in oxygen saturation (as measured by pulse oximetry) was observed, when compared to values in normoxia (80.2 ± 1.17 % (h) vs 94.12 ± 0.24 % (n); p<0.001). This desaturation was not accompanied by significant changes in plasma endothelin-1 (ET-1), big endothelin-1 (BigET-1) or nitric oxide (NO). Both pulmonary artery pressure (PAP) and oscillatory compliance (OC) were significantly greater following exercise (F[superscript omitted] = 4.74 p< 0.05), compared to pre-exercise values. These outcome variables were not different between normoxia and hypoxia. Plasma ET-1 or BigET-1 levels did not differ significantly over time or across conditions F[superscript omitted] = 4.74 p> 0.05). In conclusion, plasma ET-1 levels following 30-minutes of steady state exercise at ventilatory threshold are unrelated to decrements in oxyhaemoglobin saturation.
Genre
Thesis/Dissertation
Type
Text
Language
eng
Date Available
2011-03-21
Provider
Vancouver : University of British Columbia Library
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
DOI
10.14288/1.0077010
URI
http://hdl.handle.net/2429/32612
Degree
Master of Science - MSc
Program
Human Kinetics
Affiliation
Education, Faculty of; Kinesiology, School of
Degree Grantor
University of British Columbia
Campus
UBCV
Scholarly Level
Graduate
Aggregated Source Repository
DSpace

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For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.