Nitric oxide-dependent neutrophil recruitment: role in nasal secretion

Background Leukotriene B4 (LTB4), an inflammatory mediator, is a potent che moattractant for neutrophils that plays an important role in nasal secretio n via release of elastase. Nitric oxide (NO) is an important modulator of l eucocyte-endothelial cell interactions, endogenously produced in large quan tities in the paranasal sinuses. Objective To examine the role of NO in LTB4-stimulated nasal secretion. Methods A newly-developed method for isolating and superfusing a nasal segm ent in dogs was used. Results Instillation of LTB4 into the nasal segment caused a time-dependent increase in the volume of airway fluid and in the recruitment of neutrophi ls. N(G)-nitro-L-arginine-methylester(L-NAME), an inhibitor of NO synthase, prevented LTB4-induced neutrophil recruitment and nasal secretion. Conclusion These studies show that NO modulates LTB4-induced neutrophil rec ruitment and subsequent fluid secretion in the nose, and they suggest a the rapeutic role for NO inhibitors in modulating neutrophil-dependent nasal se cretion.