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.