Identification of N- and O-linked oligosaccharides in human seminal vesicles

The main oligosaccharide residues and the saccharide linkage in infantile a nd adult human seminal Vesicles were studied by means of lectin histochemis try at light and electron microscopy levels. In adult glands, the epithelia l cell cytoplasm and luminal content reacted positively to the following re sidues: (GlcNAc)n (WGA), Gal beta1,3GalNAc (PNA), GalNAc alpha1,3Gal (SBA), GalNAc alpha1,BGalNAc (HPA), Fuc alpha1,2Gal beta1,4GlcNAc (UEA-I), and al phaL-Fuc1,6DGlcNAc-O-Melibiose (AAA). The presence of intense staining in t he luminal content suggest that glycoproteins containing these oligosacchar ide moieties are secreted by epithelial cells. Adult epithelial cells also reacted to Neu5Ac alpha2,6Gal (SNA), Neu5Ac alpha2,3Gal beta1,4GlcNAc (MAA) , Gal beta1,4GlcNAc (DSA), branched mannose chains (ConA), Man1,3Man (GNA), and Fuc alpha1,2Gal beta1,4GlcNAcFuc alpha1,3GlcNAc (LTA) but reaction to these residues was weak (MAA, DSA, ConA, and LTA) or absent (SNA and GNA) i n the gland lumen, which suggests that they belong to intracytoplasmic prot eins. The chemical and enzymatic treatments used suggest that the residues recognized by SNA, MAA, PNA, DSA, HPA, and SEA belong to O-linked oligosacc harides; those residues localized by ConA and GNA have an N-glycosidic link age, and those bound by WGA, LTA, UEA-I, and AAA are linked to both N- and O-oligosaccharides. In prepubertal seminal vesicles, reaction in the epithe lial cell cytoplasm was similar to that observed in adults, except for GNA and HPA, which showed a weaker reaction. However, the lumen of prepubertal seminal vesicles showed intense reaction to WGA and SEA only. The chemical and enzymatic treatments suggest that the scanty glycoproteins secreted by the prepubertal glands belong to the mucin-type.