A LECTIN HISTOCHEMICAL-STUDY OF GUSTATORY (VON EBNERS) GLANDS OF THE HORSE TONGUE

In the present work, gustatory glands (von Ebner's glands) of the hors e tongue were examined by means of five peroxidase-conjugated lectins (PNA, DBA, SEA, UEA I, WGA), with and without prior sialidase digestio n, in order to investigate the presence and distribution of carbohydra te residues in secretory cells and duct cells. The most intense staini ng of secretory cells was observed with PNA after pre-treatment with n euraminidase. This indicates that the terminal trisaccharide sequence sialic acid- (alpha 2-->3, 6) galactosyl (beta 1-->3) N-acetylgalactos amine is the most frequent oligosaccharide chain present in glycoprote ins secreted by horse gustatory glands. Secretory cells also contained oligosaccharides with terminal alpha-N-acetylgalactosamine and N-acet ylglucosamine, whereas fucose was found in only a few glandular cells. The apical cytoplasm of duct lining cells reacted with all the lectin s except WGA.