[Expression of nitric oxide synthase and its significance in nasal polyps].

OBJECTIVE

To study the expression of nitric oxide synthase (NOS) and its activity in nasal polyps and its significance.

METHOD: Septectomy and immunohistochemisty were used to examine NOS activity and identify the expression of inducible NOS (iNOS) and endotheial NOS (eNOS) in human nasal specimens from patients undergoing nasal spectrumtomy (n = 20) or nasal polypectomy (n = 30).

RESULT: The activity of NOS was significantly higher in nasal polyps than in nasal mucosa (4.079 +/- 0.655) U/Pro vs (1.526 +/- 0.310) U/Pro (P<0.01). iNOS reaction product was located in epithelial cells, vascular endothelial cells, nasal glands and inflammation cells of nasal polyps. iNOS reaction product almost was not be founded in nasal mucosa. Amount of. iNOS positive cells in nasal polyps was higher than in nasal mucosa (P<0.01). eNOS reaction product were located in nasal polyps and nasal mucosa. There was no quantitative difference of eNOS between in nasal polyps and nasal mucosa. Amount of iNOS positive cells was significantly higher than of eNOS positive cells in nasal polyps (P<0.01).

CONCLUSION

iNOS, mainly expressed in nasal polyps, locates in epithelial cells and vascular endothelial cells and nasal glands and inflammation cells in nasal polyps, which produce NO at high concentration that plays an important role in the formation of nasal polyps.