Ozone-induced release of neuropeptides from human nasal mucosa cells

Studies examining the effect of pharmacological agents on respiratory responses to ozone support the concept that the effects are mediated, at least in part, by neural mechanisms, including neuropeptide release. Using a special tissue culture system the influence of ozone (0.1 ppm/24 h) on nasal mucosa from allergic and nonallergic patients undergoing surgery for chronic nasal obstruction was examined. Substance P (SP)-immunoreactive nerves were found in air-exposed as well as in ozone-exposed tissue samples. The content of neurokinin A (NKA) and SP in the culture supernatants was significantly increased following ozone exposure compared to controls. Tissue of allergic patients showed an ozone-induced increase in the release of NKA and SP compared to tissue of nonallergic patients. These results suggest that the mode of action of ozone results in an increased activity of sensory nerves in the upper airways with a subsequent increased release of neuropeptides. In addition to the known ozone-induced release of proinflammatory mediators, these mechanisms may explain the increased responsiveness of patients with hypersensitive airways.