title: The effect of topical capsaicin-induced sensitization on heat-evoked cutaneous vasomotor responses.
abstract: Brief, localized, cutaneous, non-painful thermal stimuli can evoke a transient vasomotor response, causing increased cutaneous blood flow and elevated skin temperature. The aims of this study were to investigate 1) if cutaneous sensitization by topical application of capsaicin (TRPV1 receptor agonist) can facilitate the size, duration and spatial extent of this vasomotor response and 2) if males and females respond differently. Thermal pulses (43°C for 60 seconds) were applied on left/right volar forearms of 15 age-matched males and females. Skin temperature and cutaneous blood flow were measured 1, 5, 10, 15, and 30 minutes after heat application before and after topical capsaicin (1%, 30 min application) with contralateral arm serving as the control. Recordings were made from the region of interest at distances of 2, 4, 6, 8, and 10 cm from the capsaicin application site. Sensitization significantly enhanced skin temperature for up to 30 min and compared with non-sensitized skin at 10 min. Females showed the strongest response after sensitization, but the response lasted longer and spread more widely in males. The blood flow responses were significantly longer after capsaicin (from 5 to 30 minutes after thermal application). This increased blood flow extended outside the treated area up to 10 min after stimulation. After sensitization, the area under the blood flow response curves showed significantly stronger responses in females, spreading 4 cm outside the stimulation site. Cutaneous sensitizing caused prolonged and spatially expanded vasomotor responses to standardized thermal stimulation with sex specific differences.
authors.affiliation: Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Faculty of Medicine, Aalborg University Aalborg, Denmark.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Nielsen
authors.forename: Larissa Bittencourt
authors.initials: LB
authors.lastname: da Silva
authors.forename: Lars
authors.initials: L
authors.lastname: Arendt-Nielsen
authors.forename: Parisa
authors.initials: P
authors.lastname: Gazerani
keywords: Neurogenic inflammation; capsaicin; cutaneous; sensitization; thermal stimulation; vasomotor response
references.citation: Nat Biotechnol. 2008 Nov;26(11):1261-8
references.pmid: 18997767
references.citation: Int J Physiol Pathophysiol Pharmacol. 2011;3(4):257-65
references.pmid: 22162782
references.citation: J Appl Physiol (1985). 2001 Oct;91(4):1619-26
references.pmid: 11568143
references.citation: Eur J Pharmacol. 1987 Nov 10;143(2):267-73
references.pmid: 2446892
references.citation: Pain. 2005 Nov;118(1-2):155-63
references.pmid: 16202522
references.citation: Pain Med. 2000 Sep;1(3):225-30
references.pmid: 15101888
references.citation: Acta Diabetol Lat. 1983 Apr-Jun;20(2):175-8
references.pmid: 6349204
references.citation: Microvasc Res. 2010 Dec;80(3):505-11
references.pmid: 20542492
references.citation: Clin Pharmacokinet. 1998 Apr;34(4):311-22
references.pmid: 9571303
references.citation: Clin Pharmacol Ther. 1996 Sep;60(3):308-15
references.pmid: 8841153
references.citation: Eur J Dermatol. 2009 Jul-Aug;19(4):309-23
references.pmid: 19443302
references.citation: Cochrane Database Syst Rev. 2012 Sep 12;(9):CD010111
references.pmid: 22972149
references.citation: Clin Dermatol. 1995 Jul-Aug;13(4):337-47
references.pmid: 8665442
references.citation: Cancer Res. 1984 Oct;44(10 Suppl):4721s-4730s
references.pmid: 6467226
references.citation: Allergy. 1990 Feb;45(2):121-5
references.pmid: 2316822
references.citation: J Orofac Pain. 2007 Fall;21(4):289-302
references.pmid: 18018990
references.citation: Int J Physiol Pathophysiol Pharmacol. 2011 Sep 30;3(3):202-9
references.pmid: 21941611
references.citation: Br J Dermatol. 2010 May;162(5):1023-9
references.pmid: 20030637
references.citation: J Neurophysiol. 1999 Nov;82(5):2602-11
references.pmid: 10561430
references.citation: Microvasc Res. 2012 Mar;83(2):162-7
references.pmid: 21763703
references.citation: Clin Neurophysiol. 2012 Jul;123(7):1429-36
references.pmid: 22188747
references.citation: Int J Physiol Pathophysiol Pharmacol. 2011 Sep 30;3(3):236-42
references.pmid: 21941614
references.citation: Eur J Clin Pharmacol. 1992;43(6):625-8
references.pmid: 1493844
references.citation: J Dermatol Sci. 2012 Feb;65(2):81-5
references.pmid: 22154816
references.citation: J Pain Palliat Care Pharmacother. 2011;25(1):32-41
references.pmid: 21426216
references.citation: Pain. 2005 Sep;117(1-2):223-9
references.pmid: 16098662
references.citation: J Pain Res. 2011;4:365-71
references.pmid: 22090805
references.citation: J Neurophysiol. 2000 Nov;84(5):2695-8
references.pmid: 11068011
references.citation: J Pharm Sci. 1994 Jun;83(6):783-91
references.pmid: 9120806
references.citation: Skin Pharmacol. 1989;2(3):162-7
references.pmid: 2627417
references.citation: Pain. 2012 Mar;153(3):602-618
references.pmid: 22192712
references.citation: Somatosens Mot Res. 2009 Dec;26(4):75-81
references.pmid: 20047508
references.citation: Intensive Care Med. 2005 Oct;31(10):1316-26
references.pmid: 16170543
references.citation: Am Heart J. 1986 Sep;112(3):537-41
references.pmid: 3092610
references.citation: Brain. 1989 Oct;112 ( Pt 5):1317-31
references.pmid: 2804614
references.citation: Brain Res. 1998 May 4;792(1):1-9
references.pmid: 9593798
references.citation: Brain Res. 2009 Jun 18;1276:103-11
references.pmid: 19374887
references.citation: Front Biosci (Schol Ed). 2010 Jun 01;2:825-53
references.pmid: 20515828
references.citation: Eur Neurol. 2012;68(5):264-75
references.pmid: 23037991
references.citation: Neurosci Biobehav Rev. 2010 Feb;34(2):177-84
references.pmid: 19822171
references.citation: Arch Dermatol. 2003 Nov;139(11):1479-88
references.pmid: 14623709
references.citation: J Dent Res. 1972 Mar-Apr;51(2):264-9
references.pmid: 4551675