title: Allergen challenge during halothane compared to isoflurane anesthesia induces a more potent peripheral lung response.
abstract: Allergen instillation in anaesthetized vs. awake animals results in increased distribution of allergen in the lung. Halothane is a more potent bronchodilator of the small airways than isoflurane. As small airways contribute to asthma pathogenesis, we questioned whether intranasal challenge under halothane vs. isoflurane anesthesia would lead to an increase in allergen deposition in the lung periphery and, consequently, an enhanced allergic response. C57Bl/6 mice were sensitized twice and repeatedly challenged with ovalbumin (OA) under halothane or isoflurane anesthesia. After OA-challenge, in vivo lung function was measured and BAL performed. Peribronchial and peripheral inflammation, cytokine mRNA production and collagen deposition were assessed. Airway hyperresponsiveness, BAL eosinophilia, peripheral lung inflammation, IL-5 mRNA production and collagen deposition were significantly increased in halothane OA-challenged compared to isoflurane OA-challenged mice. Airway challenge induced a higher level of airway hyperresponsiveness, inflammation and remodeling under halothane than isoflurane anesthesia in a murine model of asthma. These differences may be due to increased allergen deposition in the small airways.
authors.affiliation: Department of Internal Medicine, University of Sao Paulo Medical School at Ribeirao Preto, SP, Brazil. Electronic address: marcoscborges@hotmail.com.
authors.forename: Marcos C
authors.initials: MC
authors.lastname: Borges
authors.forename: Cinzia L
authors.initials: CL
authors.lastname: Marchica
authors.forename: Venkatesan
authors.initials: V
authors.lastname: Narayanan
authors.forename: Mara S
authors.initials: MS
authors.lastname: Ludwig
mesh_terms: D000485:Allergens / Q000276:immunology*; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D016535:Bronchial Hyperreactivity / Q000276:immunology*; D001985:Bronchial Provocation Tests / Q000379:methods; D006221:Halothane / Q000494:pharmacology*; D007530:Isoflurane / Q000494:pharmacology*; D008168:Lung / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D009299:Nasal Provocation Tests / Q000379:methods*
chemical_list: D000485:Allergens; D018685:Anesthetics, Inhalation; D007530:Isoflurane; D006221:Halothane
keywords: Airway hyperresponsiveness; Animal model; Forced oscillation technique; Inflammation; Remodeling; Small airways