Distinctive patterns of release of neuroendocrine peptides after nasal challenge of allergic subjects with ryegrass antigen.

The concentrations of the neuropeptides substance P, somatostatin, and calcitonin gene-related peptide in human nasal secretions were quantified by radioimmunoassays, concurrently with that of histamine, in the course of nasal challenge of allergic and control subjects with ryegrass antigen to examine contributions of neuromediation of the tissue response. Each of the neuropeptides and histamine were detected in nasal lavage fluid prior to challenge. In allergic patients, but not normal controls, antigen evoked significant increases of 3-fold in histamine at 15-60 min, 1.5- to 4-fold in calcitonin gene-related peptide at 15 min-24 hr, and more than 2-fold in somatostatin at 6 hr, without altering the concentration of substance P in nasal lavage fluid. The identity of the neuropeptides was confirmed chromatographically. Thus calcitonin gene-related peptide may mediate nasal congestion directly and somatostatin may be one of the factors regulating the late involvement of basophils and mast cells in allergic rhinitis.