A lectin histochemical study of gustatory (von Ebner’s) glands of the horse tongue.

This research reports a study where various techniques were used to examine the structure and composition of the gustatory glands (specifically the von Ebner’s glands) in horse tongues. The aim was to recognize and identify the types of carbohydrate residues within secretory and duct cells of the glands.

Methods Used

• The researchers used peroxidase-conjugated lectins, which are proteins that bind to specific carbohydrate molecules, to analyze the samples. These included PNA, DBA, SBA, UEA I, and WGA.
• Some samples were treated with sialidase, an enzyme that catalyzes the hydrolysis of sialic acids, before analysis.

Observations and Findings

• After the application of sialidase, the use of PNA resulted in the most intense staining of the secretory cells. This indicated a high presence of the trisaccharide sequence sialic acid- (alpha 2–>3, 6) galactosyl (beta 1–>3) N-acetylgalactosamine. This sequence is a type of oligosaccharide chain that is commonly found in glycoproteins, proteins which have carbohydrate molecules attached, secreted by horse gustatory glands.
• The researchers also found oligosaccharides with terminal alpha-N-acetylgalactosamine and N-acetylglucosamine in secretory cells.
• Fucose, a type of sugar, was found only in some of the glandular cells.
• The apical cytoplasm of cells lining the gland ducts reacted with all the lectins used for the study, except WGA.

Implications of Findings

• The study provides a detailed examination of the carbohydrate composition of horse gustatory glands and identifies the key carbohydrates present.
• Findings can be used as a base for comparison with similar studies made on other species or used as a baseline in related research on horses.