title: Regional relation between skin blood flow and sweating to passive heating and local administration of acetylcholine in young, healthy humans.
abstract: Regional variation in sweating over the human body is widely recognized yet variation in vasomotor responses and mechanisms causing this variation remain unclear. This study aimed to explore the relation between regional sweating rates (RSR) and skin blood flow (SkBF) responses to thermal and pharmacological stimuli in young, healthy subjects. In nine subjects (23 ± 3 yr), intradermal microdialysis (MD) probes were inserted into the ventral forearm, abdomen, thigh, and lower back and perfused with lactated Ringer solution. RSR over each MD membrane were measured using ventilated capsules with a laser Doppler probe housed in each capsule for measurement of red cell flux (laser Doppler flux, LDF) as an index of SkBF. Subjects completed a whole body heating protocol to 1°C rise in oral temperature and an acetylcholine dose response (ACh 1 × 10(-7)-0.1 M; mean skin temperature 34°C). Maximal LDF were obtained at the end of both protocols (50 mM sodium nitroprusside).During heating RSR varied among sites (P < 0.0001) and was greater on the back versus other sites (P < 0.05), but LDF was similar between sites (P = 0.343). RSR and SkBF showed a strong relation during initial (arm: r = 0.77 ± 0.09, thigh: r = 0.81 ± 0.08, abdomen: r = 0.89 ± 0.04, back: r = 0.86 ± 0.04) but not latter stages of heating. No differences in RSR (P = 0.160) or SkBF (LDF, P = 0.841) were observed between sites during ACh perfusion. Taken together, these data suggest that increases in SkBF are necessary to initiate and increase sweating, but further rises in RSR are not fully dependent on SkBF in a dose-response manner. Furthermore, RSR cannot be explained by cholinergic sensitivity or variation in SkBF.
authors: Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA. cus19@psu.edu
authors: Caroline J
authors: CJ
authors: Smith
authors: W Larry
authors: WL
authors: Kenney
authors: Lacy M
authors: LM
authors: Alexander
mesh_terms: D000109:Acetylcholine / Q000008:administration & dosage / Q000494:pharmacology*; D000328:Adult; D004305:Dose-Response Relationship, Drug; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D012867:Skin / Q000098:blood supply*; D013546:Sweating / Q000502:physiology*; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D014665:Vasodilator Agents; D000109:Acetylcholine
references: J Appl Physiol (1985). 2011 Dec;111(6):1703-9
references: 21868682
references: Eur J Appl Physiol. 2008 Sep;104(2):245-55
references: 18064483
references: J Physiol. 2005 Nov 1;568(Pt 3):1047-56
references: 16123103
references: J Appl Physiol (1985). 2011 May;110(5):1406-13
references: 21292837
references: J Appl Physiol (1985). 2001 Mar;90(3):757-62
references: 11181580
references: Eur J Appl Physiol. 2008 Sep;104(2):257-64
references: 18157675
references: J Appl Physiol. 1948 Jul;1(1):53-9
references: 18887575
references: Aviat Space Environ Med. 2008 Nov;79(11):1034-40
references: 18998484
references: Med Sci Sports Exerc. 2012 Dec;44(12):2350-61
references: 22811031
references: J Appl Physiol (1985). 1990 Dec;69(6):2149-54
references: 1706332
references: Circ Res. 1995 Dec;77(6):1222-8
references: 7586235
references: Metabolism. 2011 Jul;60(7):976-81
references: 21040937
references: Jpn J Physiol. 1986;36(2):417-22
references: 2874251
references: Eur J Appl Physiol Occup Physiol. 1995;71(6):549-54
references: 8983924
references: J Physiol. 1959 Oct;148:615-24
references: 13811290
references: Fed Proc. 1973 May;32(5):1583-7
references: 4705204
references: Eur J Appl Physiol Occup Physiol. 1996;74(1-2):78-84
references: 8891504
references: Aviat Space Environ Med. 2006 Oct;77(10):1020-7
references: 17042246
references: Clin Physiol. 1986 Aug;6(4):337-46
references: 3527533
references: Am J Physiol Heart Circ Physiol. 2007 Aug;293(2):H1090-6
references: 17483240
references: J Physiol. 2007 Jun 1;581(Pt 2):863-72
references: 17347269
references: J Appl Physiol (1985). 1988 Sep;65(3):1082-6
references: 3182477
references: J Appl Physiol (1985). 2002 Nov;93(5):1644-9
references: 12381749
references: Eur J Appl Physiol Occup Physiol. 1998 Dec;79(1):17-23
references: 10052655
references: J Physiol. 2005 Mar 15;563(Pt 3):965-73
references: 15661816
references: J Physiol. 2003 Oct 1;552(Pt 1):223-32
references: 12847205
references: Eur J Appl Physiol. 2008 Sep;104(2):265-70
references: 18157726
references: J Appl Physiol. 1948 Sep;1(3):234-41
references: 18885668
references: J Appl Physiol. 1957 Mar;10(2):242-8
references: 13428653
references: J Appl Physiol (1985). 2010 Nov;109(5):1301-6
references: 20705945
references: Jpn J Physiol. 1987;37(5):929-36
references: 3329689
references: J Appl Physiol. 1971 Jul;31(1):80-7
references: 5556967
references: J Physiol. 2007 Nov 15;585(Pt 1):295-303
references: 17901123
references: J Physiol. 1962 Jun;162:121-8
references: 14466872
references: J Appl Physiol (1985). 2007 May;102(5):1856-61
references: 17234802
references: Eur J Appl Physiol. 2011 Jul;111(7):1391-404
references: 21153660
references: Am J Physiol Regul Integr Comp Physiol. 2012 Mar 1;302(5):R634-42
references: 22170619
references: Eur J Appl Physiol Occup Physiol. 1995;71(1):33-40
references: 7556130