Visualization of carbohydrate chains in rabbit salivary glands by means of enzymatic degradation and plant lectins.

We investigated the structure of glycoconjugates contained within the secretory end-pieces and ductal segments in the rabbit submandibular and sublingual glands. Glycosidic sequences were examined by means of enzymatic degradation with specific glycosidases (sialidase, alpha-fucosidase, beta-galactosidase, alpha-mannosidase) followed by lectin binding with PNL-HRP, WPL-HRP, WGL-HRP, SBL-HRP, Con A-HRP. It was found that this procedure represents a valid tool for studying carbohydrates, in so far as their characterization and localization were based only on colour reactions. In particular, this research showed that sialic acid was present in the terminal dimers sialic acid-beta-galactose and sialic acid-N-acetyl-D-galactosamine within the submandibular gland, whereas in the sublingual gland it was only present as the sequence sialic acid-beta-galactose. Conversely, fucose had as the subterminal sugar N-acetyl-D-glucosamine in both glands. Also, elucidations about structural sequences concerning other non-terminal sugars were obtained.