Peripheral mechanisms of thermoregulatory control of skin blood flow in aged humans.
Human skin blood flow is controlled via dual innervation from the sympathetic nervous system. Reflex cutaneous vasoconstriction and vasodilation are both impaired with primary aging, rendering the aged more vulnerable to hypothermia and cardiovascular complications from heat-related illness. Age-related alterations in the thermoregulatory control of skin blood flow occur at multiple points along the efferent arm of the reflex, including 1) diminished sympathetic outflow, 2) altered presynaptic neurotransmitter synthesis, 3) reduced vascular responsiveness, and 4) impairments in downstream (endothelial and vascular smooth muscle) second-messenger signaling. This mechanistic review highlights some of the recent findings in the area of aging and the thermoregulatory control of skin blood flow.
Holowatz
Lacy A
LA
Department of Kinesiology, The Pennsylvania State University, Noll Laboratory, University Park, PA 16802, USA. Lma191@psu.edu
Kenney
W Larry
WL
D000375:Aging; D001833:Body Temperature Regulation; D006439:Hemodynamics; D006801:Humans; D008833:Microcirculation; D055806:Microvessels / Q000294:innervation*; D012018:Reflex; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply*; D013564:Sympathetic Nervous System / Q000502:physiology*; D014661:Vasoconstriction; D014664:Vasodilation