Sialoglycoconjugate expression in acinar cells of rat developing submandibular gland.

Direct and indirect staining procedures were developed to characterize sialoglycoconjugates in developing rat submandibular gland. Lectin histochemistry, with and without prior sialidase digestion, combined with differential oxidation and deacetylation procedures was performed in situ. This allowed the expression of sialic acids to be followed during acinar cell development. It was found that terminal periodate-labile sialic acids linked to beta-galactose occurred early. In contrast, the terminal disaccharide sialic acid-N-acetylgalactosamine was only detectable at the adult stage and so was considered to be a good marker of the full maturity of this gland. The developing acinar cells were mainly characterized by C4-acetylated sialic acids belonging to short side-chains. Dimorphic expression of sialoglycoconjugate components was evident by postnatal day 44.