title: Ultrastructural localization of concanavalin A in the perfused rat heart.
abstract: Staining of the surface coat of heart capillaries and aorta was achieved by perfusing concanavalin A and phytohemagglutinin coupled to horseradish peroxidase through the rat heart. The binding of these lectins provides evidence for the presence of glycoproteins containing mannose, glucose, and N-acetylgalactosamine residues in the endothelial surface coat of rat aorta and heart capillaries. The binding of concanavalin A to capillary endothelium was further followed with radioautography of 125I-labeled concanavalin A in the in vitro perfused rat heart. Following the shorter time intervals of perfusion more than 80 per cent of labeled concanavalin A was releasable by alpha-methyl-D-mannoside and the radioautographic reaction was confined to the endothelial cell surface. Following 60 minutes of perfusion with concanavalin A there was translocation of part of the lectin to the extravascular space and evidence of endothelial cell swelling. A tentative estimate of the concanavalin A binding sites in capillary endothelium was determined to be approximately 5000 per sq. mum.
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism; D001665:Binding Sites; D002196:Capillaries / Q000378:metabolism* / Q000648:ultrastructure; D003208:Concanavalin A / Q000378:metabolism* / Q000494:pharmacology; D003331:Coronary Vessels / Q000378:metabolism*; D004727:Endothelium / Q000378:metabolism; D005260:Female; D006023:Glycoproteins / Q000378:metabolism; D006321:Heart / Q000187:drug effects; D006651:Histocytochemistry; D008854:Microscopy, Electron; D009206:Myocardium / Q000473:pathology; D051381:Rats; D011955:Receptors, Drug
chemical_list: D006023:Glycoproteins; D011955:Receptors, Drug; D003208:Concanavalin A