The impact of high altitude on endothelial function in humans
department or school: Health and Social Development, Faculty of (Okanagan)
department or school: Health and Exercise Sciences, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Tymko, Michael Martin
issued: 2019-05-22T15:47:36Z
issued: 2019
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Previous work has demonstrated that ascent to high altitude results in endothelial impairment (i.e. reduced); however, the mechanism(s) governing this impairment remain unclear. The overall objective of the current thesis, addressed in three separate studies, was to determine the role of the sympathetic nervous system (SNS) on endothelial function after ascent to high altitude. Study #1 investigated the effects of exercise-induced elevations in sympathetic nervous activity (SNA) on endothelial function [via non-invasive flow-mediated dilation (FMD)] at sea level (344m) and high altitude (3800m). The findings from this study demonstrated that endothelial function was not reduced at high altitude compared to sea level at rest. Furthermore, at sea-level, endothelial function was reduced via SNS related pathways after moderate intensity exercise; however, this was not observed at high altitude. Study #2 examined the influence of transient manipulations of SNA [via lower-body differential pressure] on endothelial function (via FMD) at sea level (344m) and high altitude (5050m). The primary findings indicated that endothelial function was impaired at rest, and at both sea level and high altitude, endothelial function was not altered after manipulating SNA. Based on previous investigations and studies #1 and #2 of the current thesis, we hypothesized that endothelial function was only reduced at altitudes >4000m. Study #3 assessed vascular function (via intra-arterial infusion of acetylcholine and sodium nitroprusside) at rest before and after local forearm autonomic blockade at sea level (344m) and high altitude (4300m) in lowlanders and Andean highlanders with and without excessive erythrocytosis (EE). The primary findings were that endothelial function was reduced in lowlanders at high altitude, and this reduction was abolished after local autonomic blockade. In addition, Andean participants with EE had reduced endothelial function compared to healthy Andean highlanders,…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/70243
note: The Impact of High Altitude on Endothelial Function in Humans by Michael Martin Tymko B.Sc., Mount Royal University, 2012 MSc. University of British Columbia, 2015 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Doctorate of Philosophy in THE COLLEGE OF GRADUATE STUDIES (Interdisciplinary Graduate Studies) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) May 2019 © Michael Martin Tymko, 2019 ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a thesis/dissertation entitled: The Impact of High Altitude on Endothelial Function in Humans submitted by Michael Martin Tymko in partial fulfillment of the requirements of the degree of Doctorate of Philosophy . Prof. Philip N. Ainslie Supervisor Dr. Neil Eves Supervisory Committee Member Dr. Glen Foster Supervisory Committee Member Dr. Chris West University Examiner Prof. Peter Raven External Examiner iii Abstract Previous work has demonstrated that ascent to high altitude results in endothelial impairment (i.e. reduced); however, the mechanism(s) governing this impairment remain unclear. The overall objective of the current thesis, addressed in three separate studies, was to determine the role of the sympathetic nervous system (SNS) on endothelial function after ascent to high altitude. Study #1 investigated the effects of exercise-induced elevations in sympathetic nervous activity (SNA) on endothelial function [via non-invasive flow-mediated dilation (FMD)] at sea level (344m) and high altitude (3800m). The findings from this study demonstrated that endothelial function was not reduced at high altitude compared to sea level at rest. Furthermore, at sea-level, endothelial function was reduced via SNS related pathways after moderate intensity exercise; however, this was not observed at high altitude. Study #2 examined the influence of transient manipulations of SNA [via lower-body differential pressure] on endothelial function…
has type: Thesis/Dissertation
date issued: 2019-09
is shown at: 10.14288/1.0378923
language: eng
degree discipline: Interdisciplinary Studies
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/70243