RESUMO
Vasoactive intestinal polypeptide(VIP), 28-amino acid peptide extracted from porcine duodenum first, has been known as a potent vasodilator. And, VIP is also one of the important neurotransmitters in autonomic pathways affecting secretion and vascular tone of the airway. The purpose of present study is to localize the VIP-containing nerve endings in the nasal gland of the guinea pig at ultrastructural level. For immunoelectron microscopy, adult guinea pigs(300-400g B.W.) were perfused with Zamboni fixative through the aorta and the nasal septum were removed. 20nm cryosections were made for immunocytochemistry using rabbit anti-VIP and ABC methods. After DAB reaction, sections were processed for pre-embedding method, and 70nm ultrathin sections were cut. Routine uranyl acetate and lead citrate staining were employed, and immunoreactivity was observed under transmission electron microscope. VIP-containing nerve endings were located in cytoplasmic interdigitation between acinar cells, and also found along the basal surface of the acini, excretory ducts, and myoepithelial cells as well. These findings imply that VIP might be involved in secretory activity of the nasal gland of the guinea pig.