[Autonomic innervation of feline laryngeal glands: an immuno-electronmicroscopic study]

Autonomic innervation of feline laryngeal glands was investigated immunoelectronmicroscopically using antisera for vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), and tyrosine hydroxylase (TH). A relatively dense population of immunoreactive (ir) VIP fibers was found in the vicinity of the basement membranes of glandular and myoepithelial cells. Some VIP -ir fibers contacted the basement membrane and some of the fibers penetrated the adjoining glandular cells intercellularly without making synaptic contacts with them. Ir-NPY and -TH fibers were less abundant than VIP-fibers and were distributed beneath the basement membranes of myoepithelial cells. These fibers were not encountered between glandular cells. The estimated ratio of ir-VIP, -TH and -NPY fibers was 20:4:1, based on the density of fibers in glandular tissues. Because this value was equal between serous and mucous glandular cell, these two tissues may receive the same pattern of autonomic innervation.