Prior oxygenation, but not chemoreflex responsiveness, determines breath-hold duration during voluntary apnea.

Autor: Bruce CD; Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, AB, Canada.; School of Health and Exercise Sciences, Centre for Heart, Lung and Vascular Health, Faculty of Health and Social Development, University of British Columbia, Kelowna, BC, Canada., Vanden Berg ER; Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, AB, Canada.; Department of Biology, Faculty of Science, University of Victoria, Victoria, BC, Canada.; Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada., Pfoh JR; Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, AB, Canada., Steinback CD; Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada., Day TA; Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, AB, Canada.
Jazyk: angličtina
Zdroj: Physiological reports [Physiol Rep] 2021 Jan; Vol. 9 (1), pp. e14664.
DOI: 10.14814/phy2.14664
Abstrakt: Central and peripheral respiratory chemoreceptors are stimulated during voluntary breath holding due to chemostimuli (i.e., hypoxia and hypercapnia) accumulating at the metabolic rate. We hypothesized that voluntary breath-hold duration (BHD) would be (a) positively related to the initial pressure of inspired oxygen prior to breath holding, and (b) negatively correlated with respiratory chemoreflex responsiveness. In 16 healthy participants, voluntary breath holds were performed under three conditions: hyperoxia (following five normal tidal breaths of 100% O 2 ), normoxia (breathing room air), and hypoxia (following ~30-min of 13.5%-14% inspired O 2 ). In addition, the hypoxic ventilatory response (HVR) was tested and steady-state chemoreflex drive (SS-CD) was calculated in room air and during steady-state hypoxia. We found that (a) voluntary BHD was positively related to initial oxygen status in a dose-dependent fashion, (b) the HVR was not correlated with BHD in any oxygen condition, and (c) SS-CD magnitude was not correlated with BHD in normoxia or hypoxia. Although chemoreceptors are likely stimulated during breath holding, they appear to contribute less to BHD compared to other factors such as volitional drive or lung volume.
(© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)
Databáze: MEDLINE
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