First experiences with cough sensitivity in model of allergic rhinitis induced in HDM-sensitized guinea pigs

摘要

BackgroundNowadays, the vast majority of research focusing oncough in sensitive and/or hyperreactive airways is doneon an animal model of guinea pigs intraperitoneally sensitizedby ovalbumin. There are no objections to modelanimal – the neurophysiology and neuropharmacology oftheir n. X are closest to humans. However, the choice ofovalbumin as model antigen together with the route ofadministration remains questionable – allergy to chickeneggs in humans manifests as food allergy, not respiratoryallergy. These limitations may represent possible obstaclesin translation of results in daily clinical practice.Therefore there is need to develop and validate newmodel of airway hypersensitivity, which would simulatereal-life conditions more closely and new model couldimprove translation of results. Most important indoorallergen for people are house dust mites (HDM), mostcommon species being D. pteronyssius and D. farinae.Their allergenic potential is complex – it includes immunogenicepitopes, faecal pellets, lipopolysaccharides, betaglucansand chitin.Material and methods10 male guinea pigs (strain Dunkin-Hartley) were used todevelop HDM model of airway hypersensitivity. Animalswere sensitized by 0.25% HDM aerosol (Greer Labs,USA), which they inhaled for 5 min over 5 days, followedby inhalation of 0.5% HDM in same protocol as before.Sensitization was confirmed by skin prick test (15μL;0.5% HDM applied intradermally). In SPT positive animalsthe symptoms of allergic rhinitis were induced byintranasal application of HDM (0.5%; 15μL) and thecough challenges with citric acid (0.4M) were performed.Airway resistance was measured in vivo by Pennock’smethod.ResultsProvisionally obtained data show, that the coughresponse in HDM-sensitized animals is similar toresponse of OVA sensitized animals (control vs. HDMvs. OVA – 9 vs. 16 vs. 15. cough bursts/10min). Samesimilarity is observed in cough latency (control vs. HDMvs. OVA – 180s vs. 86s vs. 80s). Airway resistance wasincreased, but statistical significance was not achieved.