Nitric oxide-dependent neutrophil recruitment:: role in nasal secretion

Background Leukotriene B4 (LTB4), an inflammatory mediator, is a potent chemoattractant for neutrophils that plays an important role in nasal secretion via release of elastase. Nitric oxide (NO) is an important modulator of leucocyte-endothelial cell interactions, endogenously produced in large quantities 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 segment 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 neutrophils. 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 recruitment and subsequent fluid secretion in the nose, and they suggest a therapeutic role for NO inhibitors in modulating neutrophil-dependent nasal secretion.