Exercise-induced potentiation of the acute hypoxic ventilatory response: Neural mechanisms and implications for cerebral blood flow.

Autor: Oliveira DM; Postgraduate Program in Translational Medicine, Department of Medicine, Paulista School of Medicine (EPM), Federal University of São Paulo (UNIFESP), São Paulo, Brazil., Rashid A; Postgraduate Program in Translational Medicine, Department of Medicine, Paulista School of Medicine (EPM), Federal University of São Paulo (UNIFESP), São Paulo, Brazil.; Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Pneumology, Department of Medicine, Paulista School of Medicine (EPM), Federal University of São Paulo (UNIFESP), São Paulo, Brazil., Brassard P; Department of Kinesiology, Faculty of Medicine, Université Laval, Québec City, QC, Canada.; Research Centre of the Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, QC, Canada., Silva BM; Postgraduate Program in Translational Medicine, Department of Medicine, Paulista School of Medicine (EPM), Federal University of São Paulo (UNIFESP), São Paulo, Brazil.; Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Pneumology, Department of Medicine, Paulista School of Medicine (EPM), Federal University of São Paulo (UNIFESP), São Paulo, Brazil.; Department of Physiology, Paulista School of Medicine (EPM), Federal University of São Paulo (UNIFESP), São Paulo, Brazil.
Jazyk: angličtina
Zdroj: Experimental physiology [Exp Physiol] 2024 Nov; Vol. 109 (11), pp. 1844-1855. Date of Electronic Publication: 2024 Mar 05.
DOI: 10.1113/EP091330
Abstrakt: A given dose of hypoxia causes a greater increase in pulmonary ventilation during physical exercise than during rest, representing an exercise-induced potentiation of the acute hypoxic ventilatory response (HVR). This phenomenon occurs independently from hypoxic blood entering the contracting skeletal muscle circulation or metabolic byproducts leaving skeletal muscles, supporting the contention that neural mechanisms per se can mediate the HVR when humoral mechanisms are not at play. However, multiple neural mechanisms might be interacting intricately. First, we discuss the neural mechanisms involved in the ventilatory response to hypoxic exercise and their potential interactions. Current evidence does not support an interaction between the carotid chemoreflex and central command. In contrast, findings from some studies support synergistic interactions between the carotid chemoreflex and the muscle mechano- and metaboreflexes. Second, we propose hypotheses about potential mechanisms underlying neural interactions, including spatial and temporal summation of afferent signals into the medulla, short-term potentiation and sympathetically induced activation of the carotid chemoreceptors. Lastly, we ponder how exercise-induced potentiation of the HVR results in hyperventilation-induced hypocapnia, which influences cerebral blood flow regulation, with multifaceted potential consequences, including deleterious (increased central fatigue and impaired cognitive performance), inert (unchanged exercise) and beneficial effects (protection against excessive cerebral perfusion).
(© 2024 The Authors. Experimental Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.)
Databáze: MEDLINE
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