Identification of N‐ and O‐Linked Oligosaccharides in Human Seminal Vesicles

Abstract

The main oligosaccharide residues and the saccharide linkage in infantile and adult human seminal vesicles were studied by means of lectin histochemistry at light and electron microscopy levels. In adult glands, the epithelial cell cytoplasm and luminal content reacted positively to the following residues: (GlcNAc)n (WGA), Galβ1,3GalNAc (PNA), GalNAcα1,3Gal (SBA), GalNAcα1,3GalNAc (HPA), Fucα1,2Galβ1,4GlcNAc (UEA‐I), and αL‐Fuc1,6DGlcNAc‐O‐Melibiose (AAA). The presence of intense staining in the luminal content suggest that glycoproteins containing these oligosaccharide moieties are secreted by epithelial cells. Adult epithelial cells also reacted to Neu5Acα2,6Gal (SNA), Neu5Acα2,3Galβ1,4GlcNAc (MAA), Galβ1,4GlcNAc (DSA), branched mannose chains (ConA), Man1,3Man (GNA), and Fucα1,2Galβ1,4GlcNAcFucα1,3GlcNAc (LTA) but reaction to these residues was weak (MAA, DSA, ConA, and LTA) or absent (SNA and GNA) in the gland lumen, which suggests that they belong to intracytoplasmic proteins. The chemical and enzymatic treatments used suggest that the residues recognized by SNA, MAA, PNA, DSA, HPA, and SBA belong to O‐linked oligosaccharides; those residues localized by ConA and GNA have an N‐glycosidic linkage, 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 epithelial 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 SBA only. The chemical and enzymatic treatments suggest that the scanty glycoproteins secreted by the prepubertal glands belong to the mucin‐type.