ABSTRACT
Neuropeptides and Nitric Oxide (NO) interact in several ways in the airways: NO and vasoactive intestinal peptide are coutilized by a subset of airway nerve fibers. The presence of isoforms of soluble guanylyl cyclase (GC) in sensory neurons suggest that they are influenced by NO-mediated mechanisms. This chapter reviews the advances on the distribution of natriuretic peptide receptors and soluble GC in the lower airways. It focuses on the sensory innervation and the coexistence of other neuropeptides with nitric oxide synthase (NOS) in the airway innervation. The lung is a major source of soluble GC and histochemistry and immuno-histochemistry revealed an almost ubiquitous distribution of soluble GC in pulmonary cells, suggesting a widespread range of NO-mediated functions. Although the predominant natriuretic receptor type identified in the lung is not coupled to guanylyl cyclase activity, rat lung membranes contain a membrane-bound GC that can be activated by atrial natriuretic peptide.
