Objective: To further carry out a quantitative immunohistochemical study on neuropeptides (NPs) participation in perennial allergic rhinitis (PAR) in nasal mucosa.
Methods: By using light microscopy (routine hematoxylin and eosin staining, Wright's staining and 1% toluidine blue staining) and scanning as well as transmission electron microscopy, an exhaustive immunohistochemical and morphometric study was made on the changes of substance P (SP), neuropeptide A (NKA) and neuropeptide B (NKB) in the nasal mucosa of a toluene-2,4-iso-cyanate (TDI)-induced PAR model of rat.
Results: The results showed that the densities of all three peptidergic terminals were significantly increased (P < 0.01) in experimental group (115.72 +/- 28.43 for SP, 39.23 +/- 10.34 for NKA and 37.24 +/- 11.22 for NKB, respectively) as compared with those in control group (49.65 +/- 11.23 for SP, 12.44 +/- 6.21 for NKA and 13.31 +/- 7.60 for NKB, respectively). Increased staining, thickening of peptidergic terminals and enlargement of varicosities were found. Mast cell infiltration in nasal mucosa was in parallel with increase of peptidergic terminals.
Conclusion: All results support the hypothesis that NP is a newly-recognized but potentially important factor in the pathogenesis of PAR.