CHANGES IN TACHYKININ-ERGIC NERVE-TERMINAL DENSITIES IN RAT NASAL-MUCOSA DURING HYPERSENSITIVITY

Objective To further carry out a quantitative immunohistochemical stud y on neuropeptides (NPs) participation in perennial allergic rhinitis (PAR) in nasal mucosa. Methods By using light microscopy (routine hema toxylin and eosin staining, Wright's staining and 1% toluidine blue st aining) and scanning as well as transmission electron microscopy, an e xhaustive immunohistochemical and morphometric study was made on the c hanges of substance P (SP), neuropeptide A (NKA) and neuropeptide B (N KB) in the nasal mucosa of a toluene-2, 4-iso-cyanate (TDT)-induced PA R model of rat. Results The results showed that the densities of all t hree peptidergic terminals were significantly increased (P<0.01) in ex perimental 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 gr oup (49.65+/-11.23 for SP, 12.44+/-6.21 for NKA and 13.31+/-7.60 for N KB, respectively). Increased staining, thickening of peptidergic termi nals and enlargement of varicosities were found. Mast cell infiltratio n in nasal mucosa was in parallel with increase of peptidergic termina ls. Conclusion All results support the hypothesis that NP is a newly-r ecognized but potentially important factor in the pathogenesis of PAR.