Relationship between histamine and physiological changes during the early response to nasal antigen provocation

Toinvestigate the temporal relationships of mediator release andphysiological changes during the early response to allergen, wechallenged allergic individuals intranasally with antigen and followedtheir responses. This was done by using small filter paper disks tochallenge one nostril and collect secretions from both the challengedand the contralateral nostril, thus enabling us to evaluate thenasonasal reflex. There was a significant increase insneezing after allergen challenge that peaked within 2 min and returnedto baseline. The weights of nasal secretions as well as nasal symptomsincreased immediately and remained significantly elevated for 20 min inboth nostrils. Nasal airway resistance increased slowly, reaching itspeak at ~6 min after challenge on the ipsilateral side, but it didnot change on the contralateral side. Histamine levelspeaked 30 s after removal of the allergen disk on the side ofchallenge, whereas albumin levels peaked after those of histamine.Lactoferrin paralleled the increase in secretion weights and occurredin both nostrils. Increasing doses of antigen produced dose-dependentincreases in all parameters, whereas control challenges produced noresponse. These studies describe a human model for the evaluation ofthe allergic response that is capable of simultaneously measuringmediator release and the physiological response, including thenasonasal reflex. This model should prove useful instudying the mechanism of allergic rhinitis in humans.