Autonomic and peptidergic innervation of human nasal mucosa

The localization and distribution of vasoactive intestinal polypeptide (VIP), peptide histidine methionine (PHM), the novel peptide helospectin, neuropeptide tyrosine (NPY) and its C-flanking peptide (C-PON), substance P and calcitonin gene-related peptide (CGRP) were studied in the middle and inferior turbinate of the human nose using sensitive immunocytochemical and radioimmunological methods. For light microscopy, double immunofluorescence and immunogold-silver staining methods were applied. Ultrastructural immunoelectronmicroscopy was performed using a pre-embedding method. In addition, semithin Epon resin sections were immunostained. The concentrations of VIP, NPY, CGRP, substance P and neurokinin A were measured using radioimmunological methods. A dense network of autonomic and peptidergic nerve fibers in the normal human nasal mucosa was demonstrated. Colocalization studies showed the coexistence of peptides with components of the autonomic nervous system. Scattered chromogranin A-, CGRP and bombesin-flanking peptide (BFP)-immunoreactive endocrine-like cells were detected within the lamina propria and in groups within exocrine ducts. Highest radioimmunoassay (RIA) tissue concentrations were detected for VIP, followed by NPY, substance P, CGRP and neurokinin A.