title: The effect of heating rate on the cutaneous vasomotion responses of forearm and leg skin in humans.
abstract: We examined skin blood flow (SkBF) and vasomotion in the forearm and leg using laser-Doppler fluxmetry (LDF) and spectral analysis to investigate endothelial, sympathetic, and myogenic activities in response to slow (0.1 °C·10 s(-1)) and fast (0.5 °C·10 s(-1)) local heating. At 33 °C (thermoneutral) endothelial activity was higher in the legs than the forearms (P ≤ 0.02). Fast-heating increased SkBF more than slow heating (P=0.037 forearm; P=0.002 leg). At onset of 42 °C, endothelial (P=0.043 forearm; P=0.48 leg) activity increased in both regions during the fast-heating protocol. Following prolonged heating (42 °C) endothelial activity was higher in both the forearm (P=0.002) and leg (P<0.001) following fast-heating. These results confirm regional differences in the response to local heating and suggest that the greater increase in SkBF in response to fast local heating is initially due to increased endothelial and sympathetic activity. Furthermore, with sustained local skin heating, greater vasodilatation was observed with fast heating compared to slow heating. These data indicate that this difference is due to greater endothelial activity following fast heating compared to slow heating, suggesting that the rate of skin heating may alter the mechanisms contributing to cutaneous vasodilatation.
authors.affiliation: Integrative Exercise Physiology Laboratory, School of Kinesiology, Ball State University, Muncie, IN 47306, United States.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Del Pozzi
authors.affiliation: Exercise Physiology Laboratory, Department of Kinesiology, The University of Alabama, Tuscaloosa, AL 35487, United States.
authors.forename: James T
authors.initials: JT
authors.lastname: Miller
authors.affiliation: Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada. Electronic address: ghodges@brocku.ca.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Hodges
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D001808:Blood Vessels / Q000294:innervation*; D004730:Endothelium, Vascular / Q000502:physiology; D005260:Female; D005542:Forearm; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D017078:Laser-Doppler Flowmetry; D035002:Lower Extremity; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000294:innervation; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply*; D012881:Skin Temperature; D013997:Time Factors; D014664:Vasodilation; D014666:Vasomotor System / Q000502:physiology; D055815:Young Adult
keywords: Endothelial; Intradermal; Local heating; Microdialysis; Myogenic; Nitric oxide; Skin blood flow; Sympathetic