title: Visualization of intracellular concanavalin A binding sites in retinal photoreceptors.
abstract: Localization of carbohydrate components in retinal photoreceptor cells and membranes was studied. Frog and rat retinas were fixed with glutaraldehyde and embedded in glycol methacrylate or in a mixture of glycol methacrylate, glutaraldehyde and urea. Thin sections were incubated with ferritin-labeled concanavalin A (F-Con A) and stained with osmium vapors. Intensive binding was observed in both rod and cone outer segments. In the rod inner segment, differential binding of F-Con A was demonstrated. While numerous ferritin granules were observed in the myoid zone, only a few were seen in the ellipsoid zone, except for a local accumulation along the plasma membrane. In the rod outer segment, Con A binding sites were closely associated with the disk membranes. Ferritin granules were observed on both sides of the membranes. The relationship between the localization of Con A binding sites and the orientation of visual pigment molecules within the rod outer segments disk membranes was discussed.
mesh_terms: D000818:Animals; D001001:Anura; D001665:Binding Sites; D008566:Membranes / Q000032:analysis; D010786:Photoreceptor Cells / Q000032:analysis* / Q000648:ultrastructure; D011894:Rana pipiens; D051381:Rats; D011952:Receptors, Concanavalin A / Q000032:analysis*; D011955:Receptors, Drug / Q000032:analysis*
chemical_list: D011952:Receptors, Concanavalin A; D011955:Receptors, Drug