Go to  Advanced Search

Endothelin-1 and oxygen saturation during exercise in normoxia and hyposia

Show full item record

Files in this item

Files Size Format Description   View
ubc_2007-0101a.pdf 5.040Mb Adobe Portable Document Format   View/Open
 
Title: Endothelin-1 and oxygen saturation during exercise in normoxia and hyposia
Author: Giles, Luisa
Degree Master of Science - MSc
Program Human Kinetics
Copyright Date: 2007
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.
URI: http://hdl.handle.net/2429/32612
Series/Report no. UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/]
Scholarly Level: Graduate

This item appears in the following Collection(s)

Show full item record

All items in cIRcle are protected by copyright, with all rights reserved.

UBC Library
1961 East Mall
Vancouver, B.C.
Canada V6T 1Z1
Tel: 604-822-6375
Fax: 604-822-3893