NEUROPEPTIDES IN THE HUMAN NASAL-MUCOSA

In the present study, a dense network of peptide-immunoreactive nerve fibers in the human nasal mucosa is reported. The occurrence, distribution and concentrations of regulatory peptide immunoreactivities in human nasal mucosa were studied using highly efficient immunocytochemical and radioimmunological methods. Stefanini/Zamboni-fixed cryostat and paraffin thick sections, and Epon semithin and ultrathin sections were immunostained using multiple immunofluorescence, immunogold-silver staining (IGSS) and streptavidin-biotin-peroxidase complex (ABC) techniques. The tissue concentrations of vasoactive intestinal polypeptide (VIP), neuropeptide tyrosine (NPY), calcitonin gene-related peptide (CGRP), substance P (SP) and neurokinin A were measured using radioimmunoassay. In the tissues investigated, VIP and other derivatives from the VIP-precursor (peptide histidine methionine = PHM) prepro VIP (111 - 122), as well as NPY and its C-flanking peptide (C-PON), CGRP, SP, neurokinin A. bombesin-flanking peptide and somatostatin were detected. The regulatory peptides demonstrated also included the recently isolated peptides helospectin and pituitary adenylate cyclase activating peptide (PACAP). Scattered endocrine-like cells were demonstrated within the respiratory epithelium and the lamina propria of the nasal mucosa, and in groups within ducts. The peptide immunoreactive demonstrated in a dense network of neuronal structure and endocrine cells give indication for the presence of a complex regulatory system with potent physiological mechanisms in the upper respiratory system and allocated tissues of man.