A comparative study of vitreous-body and zonular glycoconjugates that bind to the lectin from Ulex europaeus

Eyes from adult rodents, rabbits and humans were fixed in formalin, embedded in paraffin and incubated with a horseradish peroxidase-conjugated lectin from Ulex europaeus to localize vitreous-body and zonular glycoconjugates. Rodent eyes had reaction product for peroxidase activity in fibrous structures in the posterior chamber, vitreous base and vitreous cortex. The zonules and the internal limiting membrane region of the retina also were stained. Rabbit eyes had more stained fibrous material in the vitreous base than rodent eyes and the attachment region of the zonules on the lens capsule, the anterior hyaloid membrane and tracts in the vitreous cortex were more heavily stained in rabbits. There was heavy staining of the thick vitreous base in the human eyes as well as staining of zonules, anterior hyaloid membrane and vitreous cortex. The localization of this lectin may be specific for fucose in glycoproteins or other glycoconjugates, although this was not demonstrated here. However, the location of lectin binding sites correlates well with known sites of uptake of tritiated fucose and tritiated glucosamine in rabbit eyes. Eyes from the larger species studied had more lectin-binding glycoconjugates in fibrous structures in the vitreous body than those from smaller species. The amount of glycoconjugate identified in some of the lectin-binding sites may be related to some extent to the degree of stress incident upon those sites.