Regulatory peptides in the human larynx and recurrent nerves.

We studied the peptide-innervation of the human larynx (vocal cord, ventricular folds, epiglottis, subglottic region and the recurrent nerves) using immunocytochemical and radioimmunological methods. In the tissues of the larynx investigated, the following regulatory peptides were detected: vasoactive intestinal polypeptide (VIP), peptide histidine methionine (PHM), helospectin, neuropeptide Y (NPY), C-flanking peptide of NPY (C-PON), calcitonin gene-related peptide (CGRP), substance P and neurokinin. In the recurrent nerves only small numbers of peptide-immunoreactive nerve fibers were found. Most of them showed positive immunoreactivities with antibodies to PHM, NPY and C-PON, but only rare and scattered nerve fibers were positive for VIP-, CGRP- and substance P.