Carotid baroreflex control of arterial blood pressure at rest and during dynamic exercise in aging humans
Open Access
- 1 November 2010
- journal article
- research article
- Published by American Physiological Society in American Journal of Physiology-Regulatory, Integrative and Comparative Physiology
- Vol. 299 (5), R1241-R1247
- https://doi.org/10.1152/ajpregu.00462.2010
Abstract
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.Keywords
This publication has 51 references indexed in Scilit:
- Influence of ageing on carotid baroreflex peak response latency in humansJournal Of Physiology-London, 2009
- Age‐ and fitness‐related alterations in vascular sympathetic controlJournal Of Physiology-London, 2009
- Ageing and leg postjunctional α‐adrenergic vasoconstrictor responsiveness in healthy menJournal Of Physiology-London, 2007
- Increases in central blood volume modulate carotid baroreflex resetting during dynamic exercise in humansJournal Of Physiology-London, 2007
- Ageing reduces nitric‐oxide‐ and prostaglandin‐mediated vasodilatation in exercising humansJournal Of Physiology-London, 2007
- Arterial blood pressure and carotid baroreflex function during arm and combined arm and leg exercise in humansActa Physiologica Scandinavica, 2004
- Aging and the Exercise Pressor Reflex in HumansCirculation, 2003
- Exercise‐induced muscle chemoreflex modulation of spontaneous baroreflex sensitivity in manJournal Of Physiology-London, 2001
- Age-related changes in baroreflex control of heart rate and sympathetic nerve activity in healthy humansJournal of the Autonomic Nervous System, 1996
- The baroreceptor reflex and the cardiovascular changes associated with sustained muscular contraction in the catPflügers Archiv - European Journal of Physiology, 1976