Sialic acid derivatives and their distribution in rat sublingual gland acini during pre- and post-natal development

Sialoglycoconjugates in rat sublingual gland acinar cells, at different sta ges of pre- and post-natal development, were investigated in situ with spec ific lectins and by the selective removal of terminal sialic acids. Cleavag e of acetyl substituents sited in the pyranose ring and/or polyhydroxyl sid e chain was used as an additional means of characterising the glycoconjugat es. The first expression of terminal sialic acid linked to beta -galactose was found at gestational day 17 and progressive different derivatives were observed. The terminal disaccharide sialic acid-N-acetylgalactosamine was c onstantly visualized in the sublingual gland from gestational day 18. In bo th terminal disaccharides, sialic acids were characterized by variable degr ees of acetylation and were found to be highly packaged and responsible for the hydration coat. The complex data obtained indicated that the sublingua l gland is characterized by a marked fluctuation of complex sialoglycoconju gates that differ from those in the submandibular gland of the same species .