DISTRIBUTIONS OF THE CALCITONIN-GENE-RELATED PEPTIDE AND SUBSTANCE-P IN THE MONKEY LARYNX

The distribution of calcitonin gene-related peptide (CGRP)- and substa nce P (SP)-like immunoreactivity in the monkey larynx was studied with light microscopy using the immunofluorescence method. We divided the larynx into the following six regions: epiglottis, arytenoid region, f alse cords, ventricle, vocal cords and subglottis. The distribution of immunoreactivity in the epithelium and subepithelial layer was determ ined. CGRP- and SP-like immunoreactive nerve fibers were observed in a ll regions of the laryngeal epithelium except in the vocal cords. In t he epithelium of the epiglottis and arytenoid region, numerous taste b uds containing several CGRP- and SP-like immunoreactive nerve fibers w ere observed. In the subepithelial layer, CRGP- and SP-like immunoreac tive nerve fibers were observed in all regions of the larynx. In order of decreasing density, these fibers were found in the arytenoid regio n (especially the corniculate tubercle), the epiglottis, the false cor ds, the subglottis, the ventricle, and the vocal cords. In the cornicu late tubercle, CGRP- and SP-like immunoreactive nerve fibers formed a network, whereas around the cuneiform tubercle. dense CRPG- and SP-lik e immunoreactive nerve fibers were noted parallel to the basement memb rane. SP-like immunoreactive nerve fibers showed a very similar distri bution to the CRPG fibers in the epithelium and the subepithelial laye r, but SP-like fibers were sparser in all regions of the larynx. These results, together with previous findings indicate that the arytenoid region and the epiglottis of the monkey larynx play very important rol es in airway protection, swallowing, and respiration.