Lectin-binding glycoconjugates in the subfornical organ of the rat

In the rat subfornical organ (SFO), lectin-binding glycoconjugates were histochemically examined by 9 biotinylated lectins using a streptavidin-biotin peroxidase system. The strong or moderate binding of Canavalia ensiformis (Con A), Lens culinaris (LCA) and Phaseolus vulgaris erythroagglutinin (ePHA) indicated overall distributions of high mannose, intermediate, hybrid N-linked, and non-bisected, bi/triantennate N-linked complex oligosaccharides in the rat SFO. Nonsialylated terminal N-acetylglucosamines were detected throughout this organ, as revealed by its stainabilities with Triticum vulgaris (WGA) and Limax flavus (LFA). In this organ, Ricinus communis (RCA-1) specifically bound to vessel-associated structures, whereas Arachis hypogaea (PNA) reacted with selected neurons in the central and rostral regions of this organ. Dolichos biflorus (DBA) and Ulex europaeus (UEA-1) did not stain any histologic structures in the rat SFO. The results obtained in this study provide a basis for comprehensive analyses of glycoconjugates in the rat SFO.