title: Assessment of endothelial function by acetylcholine iontophoresis: impact of inter-electrode distance and electrical cutaneous resistance.
abstract: OBJECTIVE
  Endothelial function can be assessed by acetylcholine (ACh) iontophoresis with single current application. The effect of inter-electrode distance as well as electrical cutaneous resistance (ECR) on ACh dependent vasodilation has never been studied using single current application. The aims of this study are (i) to compare ACh-peak and ECR measured at different inter-electrode distances, (ii) to assess the relationship between ACh-peak and ECR, (iii) and to study the reproducibility of the ECR values.
  
  
  METHODS
  Fourteen healthy subjects were included. Using laser speckle contrast imaging, ACh-iontophoreses (0.1 mA, 30s) were performed on the forearm at a 7-day interval with an inter-electrode distance set at 5 cm. Two other inter-electrode distances were also evaluated: 10 cm and 15 cm. ECR was measured during each ACh-iontophoresis as well as the ACh-peak.
  
  
  RESULTS
  No statistical difference was found between the ACh-peak values obtained at 5 cm, 10 cm and 15 cm. ECRs were also not statistically different. An inverse relationship (r=-0.60) was found between the ACh-peak and ECR (p<0.05). The coefficient of variation of the inter-day reproducibility of the ECR values was 9.1% [6.5%-15.1%] with an intra-class-correlation coefficient of 0.93 [0.81-0.98].
  
  
  CONCLUSIONS
  Inter-electrode distance ranging from 5 cm to 15 cm changes neither the ACh-peak value nor the ECR value. ECR impacts ACh-peak values.
authors.affiliation: Laboratory of Vascular Investigations, University Hospital of Angers, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Puissant
authors.affiliation: Laboratory of Vascular Investigations, University Hospital of Angers, France; L'UNAM University, University of Angers, Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI), Unité mixte UMR CNRS 6214/INSERM U 1083, Medicine Faculty, Angers, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Abraham
authors.affiliation: L'UNAM University, University du Maine, <EA 4334>, Motricity, Interactions, and Performance, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Durand
authors.affiliation: L'UNAM University, University of Angers, LARIS - Laboratoire Angevin de Recherche en Ingénierie des Systèmes, 62 avenue Notre Dame du Lac, 49000 Angers, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Humeau-Heurtier
authors.affiliation: L'UNAM University, University of Angers, INSERM UMR 1063, Stress oxydant et pathologies métaboliques (SOPAM), Angers, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Faure
authors.affiliation: Laboratory of Vascular Investigations, University Hospital of Angers, France; L'UNAM University, University of Angers, Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI), Unité mixte UMR CNRS 6214/INSERM U 1083, Medicine Faculty, Angers, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Leftheriotis
authors.affiliation: CHU Rennes, Imagerie Coeur-Vaisseaux, F-35033 Rennes, France; INSERM Clinical Investigation Center CIC 1414, F-35043 Rennes, France. Electronic address: guillaume.mahe@chu-rennes.fr.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Mahé
mesh_terms: D000109:Acetylcholine / Q000008:administration & dosage*; D000279:Administration, Cutaneous; D000328:Adult; D017097:Electric Impedance; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007478:Iontophoresis; D008297:Male; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012867:Skin / Q000098:blood supply*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D014665:Vasodilator Agents; D000109:Acetylcholine