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Cardiovascular reflex contributions to sympathetic inhibition during low intensity dynamic leg exercise in healthy middle‐age

Aging augments resting muscle sympathetic nerve activity (MSNA) and sympatho‐inhibition during mild dynamic 1‐leg exercise. To elucidate which reflexes elicit exercise‐induced inhibition, we recruited 19 (9 men) healthy volunteers (mean age 56 ± 9 SD years), assessed their peak oxygen uptake (VO(2pe...

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Autores principales: Notarius, Catherine F., Badrov, Mark B., Tobushi, Tomoyuki, Keir, Daniel A., Keys, Evan, Floras, John S.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10498156/
https://www.ncbi.nlm.nih.gov/pubmed/37701968
http://dx.doi.org/10.14814/phy2.15821
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author Notarius, Catherine F.
Badrov, Mark B.
Tobushi, Tomoyuki
Keir, Daniel A.
Keys, Evan
Floras, John S.
author_facet Notarius, Catherine F.
Badrov, Mark B.
Tobushi, Tomoyuki
Keir, Daniel A.
Keys, Evan
Floras, John S.
author_sort Notarius, Catherine F.
collection PubMed
description Aging augments resting muscle sympathetic nerve activity (MSNA) and sympatho‐inhibition during mild dynamic 1‐leg exercise. To elucidate which reflexes elicit exercise‐induced inhibition, we recruited 19 (9 men) healthy volunteers (mean age 56 ± 9 SD years), assessed their peak oxygen uptake (VO(2peak)), and, on another day, measured heart rate (HR), blood pressure (BP) and MSNA (microneurography) at rest and during 1‐leg cycling (2 min each at 0 load and 30%–40% VO(2peak)), 3 times: (1) seated +2 min of postexercise circulatory occlusion (PECO) (elicit muscle metaboreflex); (2) supine (stimulate cardiopulmonary baroreflexes);and (3) seated, breathing 32% oxygen (suppress peripheral chemoreceptor reflex). While seated, MSNA decreased similarly during mild and moderate exercise (p < 0.001) with no increase during PECO (p = 0.44). Supine posture lowered resting MSNA (main effect p = 0.01) BP and HR. MSNA fell further (p = 0.04) along with diastolic BP and HR during mild, not moderate, supine cycling. Hyperoxia attenuated resting (main effect p = 0.01), but not exercise MSNA. In healthy middle‐age, the cardiopulmonary baroreflex and arterial chemoreflex modulate resting MSNA, but contrary to previous observations in young subjects, without counter‐regulatory offset by the sympatho‐excitatory metaboreflex, resulting in an augmented sympatho‐inhibitory response to mild dynamic leg exercise.
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spelling pubmed-104981562023-09-14 Cardiovascular reflex contributions to sympathetic inhibition during low intensity dynamic leg exercise in healthy middle‐age Notarius, Catherine F. Badrov, Mark B. Tobushi, Tomoyuki Keir, Daniel A. Keys, Evan Floras, John S. Physiol Rep Original Articles Aging augments resting muscle sympathetic nerve activity (MSNA) and sympatho‐inhibition during mild dynamic 1‐leg exercise. To elucidate which reflexes elicit exercise‐induced inhibition, we recruited 19 (9 men) healthy volunteers (mean age 56 ± 9 SD years), assessed their peak oxygen uptake (VO(2peak)), and, on another day, measured heart rate (HR), blood pressure (BP) and MSNA (microneurography) at rest and during 1‐leg cycling (2 min each at 0 load and 30%–40% VO(2peak)), 3 times: (1) seated +2 min of postexercise circulatory occlusion (PECO) (elicit muscle metaboreflex); (2) supine (stimulate cardiopulmonary baroreflexes);and (3) seated, breathing 32% oxygen (suppress peripheral chemoreceptor reflex). While seated, MSNA decreased similarly during mild and moderate exercise (p < 0.001) with no increase during PECO (p = 0.44). Supine posture lowered resting MSNA (main effect p = 0.01) BP and HR. MSNA fell further (p = 0.04) along with diastolic BP and HR during mild, not moderate, supine cycling. Hyperoxia attenuated resting (main effect p = 0.01), but not exercise MSNA. In healthy middle‐age, the cardiopulmonary baroreflex and arterial chemoreflex modulate resting MSNA, but contrary to previous observations in young subjects, without counter‐regulatory offset by the sympatho‐excitatory metaboreflex, resulting in an augmented sympatho‐inhibitory response to mild dynamic leg exercise. John Wiley and Sons Inc. 2023-09-13 /pmc/articles/PMC10498156/ /pubmed/37701968 http://dx.doi.org/10.14814/phy2.15821 Text en © 2023 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society. https://creativecommons.org/licenses/by/4.0/This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Articles
Notarius, Catherine F.
Badrov, Mark B.
Tobushi, Tomoyuki
Keir, Daniel A.
Keys, Evan
Floras, John S.
Cardiovascular reflex contributions to sympathetic inhibition during low intensity dynamic leg exercise in healthy middle‐age
title Cardiovascular reflex contributions to sympathetic inhibition during low intensity dynamic leg exercise in healthy middle‐age
title_full Cardiovascular reflex contributions to sympathetic inhibition during low intensity dynamic leg exercise in healthy middle‐age
title_fullStr Cardiovascular reflex contributions to sympathetic inhibition during low intensity dynamic leg exercise in healthy middle‐age
title_full_unstemmed Cardiovascular reflex contributions to sympathetic inhibition during low intensity dynamic leg exercise in healthy middle‐age
title_short Cardiovascular reflex contributions to sympathetic inhibition during low intensity dynamic leg exercise in healthy middle‐age
title_sort cardiovascular reflex contributions to sympathetic inhibition during low intensity dynamic leg exercise in healthy middle‐age
topic Original Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10498156/
https://www.ncbi.nlm.nih.gov/pubmed/37701968
http://dx.doi.org/10.14814/phy2.15821
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