The late reaction following bronchial provocation with house dust mite allergen. Dependence on arachidonic acid metabolism.

The involvement of arachidonic acid metabolism in early and late bronchial reactions has been studied in four asthmatic subjects sensitive to Dermatophagoides pteronyssinus. Pre-treatment with either indomethacin (an inhibitor of the cyclo-oxygenase pathway) or benoxaprofen (an inhibitor of both cyclo-oxygenase and lipoxygenase pathways) failed to affect the amplitude, but did produce some foreshortening of the early response to allergen. If benoxaprofen is an effective inhibitor of SRS-A formation in vivo, then these observations question the role of SRS-A as a spasmogen in allergen-induced bronchospasm. Both drugs were effective inhibitors of the late reaction, implying involvement of cyclo-oxygenase products (endoperoxides, prostaglandins or thromboxanes) in the genesis of a late response to allergen.