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A comparison of antiasthma drugs between acute and chronic ovalbumin-challenged guinea-pig models of asthma.
MedLine Citation:
PMID:  23046662     Owner:  NLM     Status:  Publisher    
Pre-clinical evaluation of asthma therapies requires animal models of chronic airways inflammation, airway hyperresponsiveness (AHR) and lung remodelling that accurately predict drug effectiveness in human asthma. However, most animal models focus on acute allergen challenges where chronic inflammation and airway remodelling are absent. Chronic allergen challenge models have been developed in mice but few studies use guinea-pigs which may be more relevant to humans. We tested the hypothesis that a chronic rather than acute pulmonary inflammation model would best predict clinical outcome for asthma treatments. Guinea-pigs sensitized with ovalbumin (OVA) received single (acute) or nine OVA inhalation challenges at 48 h intervals (chronic). Airways function was recorded as specific airways conductance (sG(aw)) in conscious animals for 12 h after OVA challenge. AHR to inhaled histamine, inflammatory cell influx and lung histology were determined 24 h after the single or 9th OVA exposure. The inhaled corticosteroid, fluticasone propionate (FP), the phosphodiesterase 4 inhibitor, roflumilast, and the inducible nitric oxide synthase (iNOS) inhibitor, GW274150, orally, were administered 24 and 0.5 h before and 6 h after the single or final chronic OVA exposure. Both models displayed early (EAR) and late (LAR) asthmatic responses to OVA challenge, as falls in sG(aw), AHR, as increased histamine-induced bronchoconstriction, and inflammatory cell influx. Tissue remodelling, seen as increased collagen and goblet cell hyperplasia, occurred after multiple OVA challenge. Treatment with FP and roflumilast inhibited the LAR, cell influx and AHR in both models, and the remodelling in the chronic model. GW274150 also inhibited the LAR, AHR and eosinophil influx in the acute model, but not, together with the remodelling, in the chronic model. In the clinical setting, inhaled corticosteroids and phosphodiesterase 4 inhibitors are relatively effective against most features of asthma whereas the iNOS inhibitor GW274150 was ineffective. Thus, while there remain certain differences between our data and clinical effectiveness of these antiasthma drugs, a chronic pulmonary inflammation guinea-pig model does appear to be a better pre-clinical predictor of potential asthma therapeutics than an acute model.
Rhys L Evans; Anthony T Nials; Richard G Knowles; Emma J Kidd; William R Ford; Kenneth J Broadley
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-8-23
Journal Detail:
Title:  Pulmonary pharmacology & therapeutics     Volume:  -     ISSN:  1522-9629     ISO Abbreviation:  Pulm Pharmacol Ther     Publication Date:  2012 Aug 
Date Detail:
Created Date:  2012-10-10     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9715279     Medline TA:  Pulm Pharmacol Ther     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
Copyright © 2012 Elsevier Ltd. All rights reserved.
Division of Pharmacology, Cardiff School of Pharmacy & Pharmaceutical Technology, Cardiff University, Redwood Building, King Edward VII Avenue, Cathays Park, Cardiff CF1 3XF, United Kingdom.
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