| Carotid baroreflex control of arterial blood pressure at rest and during dynamic exercise in aging humans. | |
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MedLine Citation:
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PMID: 20826707 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The arterial baroreflex is fundamental for evoking and maintaining appropriate cardiovascular adjustments to exercise. We sought to investigate how aging influences carotid baroreflex regulation of blood pressure (BP) during dynamic exercise. BP and heart rate (HR) were continuously recorded at rest and during leg cycling performed at 50% HR reserve in 15 young (22 ± 1 yr) and 11 older (61 ± 2 yr) healthy subjects. Five-second pulses of neck pressure and neck suction from +40 to -80 Torr were applied to determine the full carotid baroreflex stimulus response curve and examine baroreflex resetting during exercise. Although the maximal gain of the modeled stimulus response curve was similar in both groups at rest and during exercise, in older subjects the operating point (OP) was located further away from the centering point (CP) and toward the reflex threshold, both at rest (OP minus CP; -10 ± 3 older vs. 0 ± 2 young mmHg, P < 0.05) and during exercise (OP minus CP; -10 ± 2 older vs. 1 ± 3 young mmHg, P < 0.05). In agreement, older subjects demonstrated a reduced BP response to neck pressure (simulated carotid hypotension) and a greater BP response to neck suction (simulated carotid hypertension). In addition, the magnitude of the upward and rightward resetting of the carotid baroreflex-BP stimulus response curve with exercise was ∼40% greater in older individuals. These data indicate that despite a maintained maximal gain, the ability of the carotid baroreflex to defend against a hypotensive challenge is reduced, whereas responses to hypertensive stimuli are greater with advanced age, both at rest and during exercise. |
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Authors:
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James P Fisher; Areum Kim; Colin N Young; Paul J Fadel |
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Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2010-09-08 |
Journal Detail:
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Title: American journal of physiology. Regulatory, integrative and comparative physiology Volume: 299 ISSN: 1522-1490 ISO Abbreviation: Am. J. Physiol. Regul. Integr. Comp. Physiol. Publication Date: 2010 Nov |
Date Detail:
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Created Date: 2010-11-03 Completed Date: 2010-12-01 Revised Date: 2011-11-01 |
Medline Journal Info:
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Nlm Unique ID: 100901230 Medline TA: Am J Physiol Regul Integr Comp Physiol Country: United States |
Other Details:
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Languages: eng Pagination: R1241-7 Citation Subset: IM |
Affiliation:
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School of Sport and Exercise Sciences, University of Birmingham, Birmingham, United Kingdom. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adaptation, Physiological Adult Age Factors Aged Aging* Baroreflex* Blood Pressure* Carotid Sinus / innervation, physiopathology* Exercise* Female Heart Rate Humans Hypertension / physiopathology* Hypotension / physiopathology* Logistic Models Male Middle Aged Photoplethysmography Rest* Sphygmomanometers Time Factors Young Adult |
| Grant Support | |
ID/Acronym/Agency:
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R01 HL093167-04/HL/NHLBI NIH HHS; R01-HL-093167/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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