UBC-Nepal expedition: The use of oral antioxidants does not alter cerebrovascular function at sea-level or high-altitude
Hansen, Alex B.
Hoiland, Ryland L.
Lewis, Nia C. S.
Tymko, Michael M.
Tremblay, Joshua C.
Carter, Howard H.
Bailey, Damian M.
MetadataShow full item record
Hypoxia is associated with an increased systemic and cerebral formation of free radicals and associated reactants that may be linked to impaired cerebral vascular function a neurological sequela. To what extent oral antioxidants prophylaxis impacts cerebrovascular function in humans throughout the course of acclimatization to the hypoxia of terrestrial high-altitude has not been examined. Thus, the purpose of the current study was to examine the influence of orally ingested antioxidants at clinically relevant doses (vitamin C, E, and alpha-lipoic acid) on cerebrovascular regulation at sea-level (344 m; n = 12; female n = 2 participants), and at high altitude (5050 m; n = 9; female n = 2), in a randomized, placebo-controlled, and double-blinded crossover design. Hypercapnic and hypoxic cerebrovascular reactivity tests of the internal carotid (ICA)] were conducted at sea-level, while global and regional cerebral blood flow [i.e. ICA and vertebral artery (VA)] were assessed after 10–12 days following arrival at 5050 m. At sea-level, acute administration of antioxidants did not alter cerebral hypoxic cerebrovascular reactivity (pre vs. post: 1.5 ± 0.7 vs. 1.2 ± 0.8 %∆CBF/-%∆SpO2; P = 0.96), or cerebral hypercapnic cerebrovascular reactivity (pre vs. post: 5.7 ± 2.0 vs. 5.8 ± 1.9 %∆CBF/∆mmHg; P = 0.33). Furthermore, global cerebral blood flow (P = 0.43), as well as cerebral vascular conductance (ICA P = 0.08; VA P = 0.32), were unaltered at 5050 m following antioxidant administration. In conclusion, these data show that an oral antioxidant cocktail known to attenuate systemic oxidative stress failed to alter cerebrovascular function at sea-level and cerebral blood flow during acclimatization to high-altitude.
Hansen, A.B., Hoiland, R.L., Lewis, N., Tymko, M.M., Tremblay, J.C., Stembridge, M., Nowak‐Flück, D., Carter, H.H., Bailey, D.M. and Ainslie, P.N. (2018) 'UBC‐Nepal expedition: The use of oral antioxidants does not alter cerebrovascular function at sea‐level or high‐altitude', Experimental Physiology. https://doi.org/10.1113/EP086887
This article was published in Experimental Physiology on 10 February 2018 (online), available at https://doi.org/10.1113/EP086887
Cardiff Metropolitan University (Grant ID: Cardiff Metropolian (Internal))
- Sport Research Groups 
Showing items related by title, author, subject and abstract.
Adenosine receptor dependent signaling is not obligatory for normobaric and hypobaric hypoxia-induced cerebral vasodilation in humans Holland, Ryan; Bain, Anthony; Tymko, Michael; Rieger, Mathew; Howe, Connor; Willie, Christopher; Hansen, Alex; Fluck, Daniela; Wildfong, Kevin; Stembridge, Mike; Subedi, Prajan; Anholm, James; Ainslie, Philip (American Physiological Society, 2017-01-12)Hypoxia increases cerebral blood flow (CBF) with the underlying signaling processes potentially including adenosine. A randomized, double-blinded, placebo controlled design, was implemented to determine if adenosine receptor ...
Carter, Howard; Spence, Angela; Pugh, Christopher J. A.; Ainslie, Philip N.; Naylor, Louise; Green, Daniel (American Physiological Society, 2014-02-19)Episodic increases in cerebrovascular perfusion and shear stress may have beneficial impacts on endothelial function that improve brain health. We hypothesized that water immersion to the level of the right atrium in humans ...
Stöhr, Eric J.; Ji, Ruiping; Akiyama, K.; Mondellini, G.; Braghieri, L.; Pinsino, A.; Cockcroft, John R.; Yuzefpolskaya, M.; Amlani, A.; Topkara, V.; Takayama, H.; Naka, Y.; Uriel, N.; Takeda, K.; Colombo, P.; McDonnell, Barry; Willey, J. (Elsevier, 2021)BACKGROUND: While rates of stroke have declined with the HeartMate3 (HM3) continuous flow (CF) left ventricular assist device (LVAD), the impact of non-pulsatile flow and artificial pulse physiology on cerebrovascular ...