title: Hypertonic saline alters electrical barrier of the airway epithelium.
abstract: OBJECTIVE
  The effect of tonicity changes in nebulizer solutions and irrigations on nasal mucosa is not well known. The present study aims to determine the basic mechanism of hypertonic solution on airway epithelial barrier.
  
  
  METHODS
  We investigated the electrical potential difference (PD) that is influenced by both active transport and the transepithelial electrical resistance of the epithelial mucosa in the human nose in vivo. The short circuit current (SCC) revealed net ion transport across the epithelium in the guinea pig trachea in vitro. Finally, the size dependency of macromolecules across the tracheal mucosa was determined in vitro using FITC-labeled dextrans of different sizes.
  
  
  RESULTS
  PD was significantly decreased after topical application of hypertonic solution both in human and in guinea pig nose. SCC was significantly decreased after application of hypertonic solution. The transport of these dextrans from the basolateral to the apical side was not increased significantly after apical application of hypertonic saline.
  
  
  CONCLUSIONS
  Hypertonic saline enhances the electrical permeability of the airway epithelial mucosa but not transport of macromolecule in the short term.
authors.affiliation: Department of Otolaryngology, Dokkyo University School of Medicine, Koshigaya Hospital, Saitama, Tokyo, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Miwa
authors.forename: Mayumi
authors.initials: M
authors.lastname: Matsunaga
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Nakajima
authors.forename: Shintaro
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Kensuke
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D003911:Dextrans / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D066298:In Vitro Techniques; D017136:Ion Transport / Q000187:drug effects*; D046911:Macromolecular Substances / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects*; D009079:Mucociliary Clearance / Q000187:drug effects; D020545:Respiratory Mucosa / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*; D014132:Trachea / Q000378:metabolism* / Q000502:physiology
chemical_list: D003911:Dextrans; D005456:Fluorescent Dyes; D046911:Macromolecular Substances; D012462:Saline Solution, Hypertonic; C015219:fluorescein isothiocyanate dextran; D016650:Fluorescein-5-isothiocyanate