LTB4-induced nasal gland serous cell secretion mediated by neutrophil elastase

Local allergen challenge causes nasal hypersecretion and also causes local leukotriene (LT) release, including LTB4. Because LTB4 causes leukocyte rec ruitment, and because neutrophil elastase is a potent secretagogue, we exam ined the hypothesis that LTB4 causes nasal hypersecretion via neutrophil el astase. We developed a method for isolating and superfusing a nasal segment in dogs. Instillation of LTB4 into the nasal segment caused a time-depende nt increase in the volume of airway fluid, in lysozyme secretion, and in th e recruitment of neutrophils. ICI 200,355, a selective inhibitor of neutrop hil elastase, prevented LTB4-induced nasal secretion and lysozyme secretion , but it had no effect on neutrophil recruitment. We conclude that LTB4 cau ses potent nasal secretion via release of elastase, and therefore LTB4 may play a major role in allergic nasal hypersecretion.