TY - JOUR

T1 - Barosensory vessel mechanics and the vascular sympathetic baroreflex: Impact on blood pressure homeostasis

AU - Hughes, Guto

AU - Moore, Jonathan

AU - Lord, Rachel

PY - 2023/10/1

Y1 - 2023/10/1

N2 - New FindingsWhat is the topic of this review?We review barosensory vessel mechanics and their role in blood pressure regulation across the lifespan.What advances does it highlight?In young normotensive men, aortic unloading mechanics contribute to the resting operating point of the vascular sympathetic baroreflex; however, with advancing age, this contribution is removed. This suggests that barosensory vessel unloading mechanics are not driving the well-documented age-related increase in resting muscle sympathetic nerve activity.An age-associated increase in arterial blood pressure is evident for apparently healthy humans. This is frequently attributed to stiffening of the central arteries and a concurrent increase in sympathetic outflow, potentially mediated by a reduced ability of the baroreceptive vessels to distend. This is supported, in part, by a reduced mechanical component of the vascular sympathetic baroreflex (i.e., a reduction in distension for a given pressure). Previous characterization of the mechanical component has assessed only carotid artery distension; however, evidence suggests that both the aortic and carotid baroreflexes are integral to blood pressure regulation. In addition, given that baroreceptors are located in the vessel wall, the change in wall tension, comprising diameter, pressure and vessel wall thickness, and the mechanics of this change might provide a better index of the baroreceptor stimulus than the previous method used to characterize the mechanical component that relies on diameter alone. This brief review summarizes the data using this new method of assessing barosensory vessel mechanics and their influence on the vascular sympathetic baroreflex across the lifespan.

AB - New FindingsWhat is the topic of this review?We review barosensory vessel mechanics and their role in blood pressure regulation across the lifespan.What advances does it highlight?In young normotensive men, aortic unloading mechanics contribute to the resting operating point of the vascular sympathetic baroreflex; however, with advancing age, this contribution is removed. This suggests that barosensory vessel unloading mechanics are not driving the well-documented age-related increase in resting muscle sympathetic nerve activity.An age-associated increase in arterial blood pressure is evident for apparently healthy humans. This is frequently attributed to stiffening of the central arteries and a concurrent increase in sympathetic outflow, potentially mediated by a reduced ability of the baroreceptive vessels to distend. This is supported, in part, by a reduced mechanical component of the vascular sympathetic baroreflex (i.e., a reduction in distension for a given pressure). Previous characterization of the mechanical component has assessed only carotid artery distension; however, evidence suggests that both the aortic and carotid baroreflexes are integral to blood pressure regulation. In addition, given that baroreceptors are located in the vessel wall, the change in wall tension, comprising diameter, pressure and vessel wall thickness, and the mechanics of this change might provide a better index of the baroreceptor stimulus than the previous method used to characterize the mechanical component that relies on diameter alone. This brief review summarizes the data using this new method of assessing barosensory vessel mechanics and their influence on the vascular sympathetic baroreflex across the lifespan.

KW - baroreflex

KW - barosensory vessel unloading mechanics

KW - healthy ageing

KW - muscle sympathetic nerve activity

KW - sympathetic nervous system

U2 - 10.1113/EP089686

DO - 10.1113/EP089686

M3 - Review article

VL - 108

SP - 1245

EP - 1249

JO - Experimental Physiology

JF - Experimental Physiology

SN - 0958-0670

IS - 10

ER -