title: Nebulized perflubron and carbon dioxide rapidly dilate constricted airways in an ovine model of allergic asthma.
abstract: BACKGROUND
  The low toxicity of perfluorocarbons (PFCs), their high affinity for respiratory gases and their compatibility with lung surfactant have made them useful candidates for treating respiratory diseases such as adult respiratory distress syndrome. We report results for treating acute allergic and non-allergic bronchoconstriction in sheep using S-1226 (a gas mixture containing carbon dioxide and small volumes of nebulized perflubron). The carbon dioxide, which is highly soluble in perflubron, was used to relax airway smooth muscle.
  
  
  METHODS
  Sheep previously sensitized to house dust mite (HDM) were challenged with HDM aerosols to induce early asthmatic responses. At the maximal responses (characterised by an increase in lung resistance), the sheep were either not treated or treated with one of the following; nebulized S-1226 (perflubron + 12% CO2), nebulized perflubron + medical air, 12% CO2, salbutamol or medical air. Lung resistance was monitored for up to 20 minutes after cessation of treatment.
  
  
  RESULTS
  Treatment with S-1226 for 2 minutes following HDM challenge resulted in a more rapid, more profound and more prolonged decline in lung resistance compared with the other treatment interventions. Video bronchoscopy showed an immediate and complete (within 5 seconds) re-opening of MCh-constricted airways following treatment with S-1226.
  
  
  CONCLUSIONS
  S-1226 is a potent and rapid formulation for re-opening constricted airways. Its mechanism(s) of action are unknown. The formulation has potential as a rescue treatment for acute severe asthma.
authors.forename: Tamer Y
authors.initials: TY
authors.lastname: El Mays
authors.forename: Parichita
authors.initials: P
authors.lastname: Choudhury
authors.forename: Richard
authors.initials: R
authors.lastname: Leigh
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Koumoundouros
authors.forename: Joanne
authors.initials: J
authors.lastname: Van der Velden
authors.forename: Grishma
authors.initials: G
authors.lastname: Shrestha
authors.forename: Cora A
authors.initials: CA
authors.lastname: Pieron
authors.forename: John H
authors.initials: JH
authors.lastname: Dennis
authors.forename: Francis Hy
authors.initials: FH
authors.lastname: Green
authors.forename: Ken J
authors.initials: KJ
authors.lastname: Snibson
mesh_terms: D000280:Administration, Inhalation; D000403:Airway Resistance / Q000187:drug effects; D000485:Allergens; D000818:Animals; D016084:Bronchoconstriction / Q000187:drug effects*; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000737:chemistry; D001999:Bronchoscopy; D002245:Carbon Dioxide / Q000008:administration & dosage* / Q000737:chemistry; D004195:Disease Models, Animal; D005260:Female; D005466:Fluorocarbons / Q000008:administration & dosage* / Q000737:chemistry; D005740:Gases; D006842:Hydrocarbons, Brominated; D006967:Hypersensitivity / Q000188:drug therapy* / Q000276:immunology / Q000503:physiopathology; D019476:Insect Proteins; D008168:Lung / Q000187:drug effects* / Q000276:immunology / Q000503:physiopathology; D010316:Particle Size; D039981:Pyroglyphidae; D012756:Sheep; D013997:Time Factors; D014741:Video Recording
chemical_list: D000485:Allergens; D001993:Bronchodilator Agents; D005466:Fluorocarbons; D005740:Gases; D006842:Hydrocarbons, Brominated; D019476:Insect Proteins; D002245:Carbon Dioxide; C003072:perflubron