title: Vasoactive properties of calcitonin gene-related peptide in human skin.
abstract: OBJECTIVE
  Calcitonin gene-related peptide (CGRP) is a potential mediator of neurogenic inflammation in eczema, psoriasis and rosacea, and also contributes to vasodilatation and oedema in complex regional pain disorder. We investigated the feasibility of administering CGRP and its antagonist CGRP8-37 by iontophoresis in human skin to characterise their vasoactive profiles.
  
  
  METHODS
  Two doses of each peptide were administered by iontophoresis (5 and 10 min duration at 0.1 mA) to the forearm skin of 6 healthy young men. Skin blood flow responses over 25 min were assessed using laser Doppler imaging.
  
  
  RESULTS
  Iontophoresis of CGRP caused a gradual change in blood flow, with no significant difference in response between each dose. The peak change in flow had a coefficient of variation of 21% to 36%, while the variability of the total cumulative response was much greater. Iontophoresis of CGRP8-37 for 5 min caused only a small, transient increase in skin blood flow, while 10 min iontophoresis resulted in a significant increase in blood flow.
  
  
  CONCLUSIONS
  CGRP and CGRP8-37 can be administered by iontophoresis to human skin. Further experiments are needed to determine the optimum duration of iontophoresis and period of measurement.
authors.affiliation: Department of Anesthesia, University of Dundee, Dundee, UK. d.j.newton@dundee.ac.uk
authors.forename: M
authors.initials: M
authors.lastname: Dias
authors.forename: D
authors.initials: D
authors.lastname: Newton
authors.forename: G
authors.initials: G
authors.lastname: McLeod
authors.forename: J J
authors.initials: JJ
authors.lastname: Belch
authors.forename: F
authors.initials: F
authors.lastname: Khan
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D001783:Blood Flow Velocity; D015740:Calcitonin Gene-Related Peptide / Q000008:administration & dosage*; D005240:Feasibility Studies; D006801:Humans; D007478:Iontophoresis; D017078:Laser-Doppler Flowmetry; D008297:Male; D010446:Peptide Fragments / Q000008:administration & dosage; D012039:Regional Blood Flow / Q000187:drug effects; D012606:Scotland; D012867:Skin / Q000098:blood supply*; D013997:Time Factors; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D010446:Peptide Fragments; D014665:Vasodilator Agents; C058636:calcitonin gene-related peptide (8-37); D015740:Calcitonin Gene-Related Peptide