IMMUNOHISTOCHEMISTRY OF GRANDRY CORPUSCLES IN THE ORAL-MUCOSA OF THE DUCK BILL - A LIGHT-MICROSCOPIC AND ELECTRON-MICROSCOPIC STUDY

Grandry corpuscles in the oral mucosa of the upper bill of the duck we re immunohistochemically studied using antisera against calcitonin gen e-related peptide (CGRP), galanin, methionine-enkephalin, neuropeptide Y (NPY), somatostatin, substance P (SP) and vasoactive intestinal pep tide (VIP). Grandry corpuscles in the lamina propria selectively showe d only SP-like immunoreactivity. Herbst corpuscles distributed near Gr andry corpuscles were negative to all antisera applied. Although immun oreactive products in the Grandry corpuscles were found as granules in the peripheral cytoplasm of the Grandry cell, the axon terminals and satellite cells exhibited no reactivity. In pre-embedding electron-mic roscopic sections, SP-like immunoreactive products visualized with 3,3 '-diaminobenzidine were localized in the granules of Grandry cells, bu t no labeling was observed in the cytoplasmic matrix or cell organelle s. Electron-immunocytochemical labeling with colloidal gold by the pos t-embedding method clearly demonstrated that the SP antigen was locali zed only in the granules. It is presumed that Grandry cells have a sec retory function. However, the function and the method of release of th e SP contained in the observed granules remains obscure. Some CGRP-, N PY-, SP- and VIP-like-immunoreactive nerve fibers with varicosities as sociated with blood vessels and nerve fiber bundles of various sizes w ere observed in the lamina propria, but no such fibers penetrated into the intraepitherial layer. Nerve fibers positive for SP and VIP were also found in the interlobular connective tissue of the palatine gland s. Some SP-positive neurons were detected in the vicinity of the palat ine glands.