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Lectin analysis of endothelial glycoconjugates in the retina of the rat
Author(s) -
Hayes A. J.,
Lawrenson J. G.,
Allt G.
Publication year - 1997
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1046/j.1475-1313.1997.97807570.x
Subject(s) - glycoconjugate , biochemistry , sialic acid , biology , lectin , galactose , glycocalyx
The vascular endothelial glycocalyx has many important functions such as mediating cell‐cell interactions and possibly a role in permeability. The aim of this study was to investigate the expression of endothelial cell (EC) glycoconjugates in retinal microvessels. Paraffin sections of fixed adult rat retina were treated with a range of biotinylated lectins followed by an avidin‐FITC conjugate. Binding sites for the lectins Canavalia ensiformis (Con A), Ricinus communis (RCA) and Triticum vulgaris (WGA) were expressed Sambicus nigra (SNA), which labels terminal sialic acid residues (NeuNAc) in a 2–6 glycosidic linkage to β galactose (βGal), and Maakia amurensis (MAA), which labels terminal sialic acid when joined in a 2–3 linkage to β galactose, both labelled strongly. In contrast, Ulex europaeus (UEA) and Glycine max (SBA) were negative Arachis hypogaea (PNA), which labels the terminal disaccharide sequence galactose β 1–3 N ‐acetylgalactosamine (GalNAc), was strongly positive only after pre‐treatment with the sialic acid digesting enzyme neuraminidase. These suggest a predominance of the oligosaccharide sequence: NeuNAc α 2–3 Gal β 1–3 GalNAc and NeuNAc α 2–6 Gal β 1–3 Gal. These sugar sequences may be significant in the function of the glycocalyx in retinal microvessels. Acknowledgement Supported by the Nuffield Foundation.