title: Studies on the orientation of brush-border membrane vesicles.
abstract: Orientation of rat renal and intestinal brush-border membrane vesicles was studied with two independent methods: electron-microscopic freeze-fracture technique and immunological methods. With the freeze-fracture technique a distinct asymmetric distribution of particles on the two membrane fracture faces was demonstrated; this was used as a criterion for orientation of the isolated membrane vesicles. For the immunological approach the accessibility or inaccessibility of aminopeptidase M localized on the outer surface of the cell membrane to antibodies was used. With both methods we showed that the brush-border membrane vesicles isolated from rat kidney cortex and from rat small intestine for transport studies are predominantly orientated right-side out.
mesh_terms: D000409:Alanine; D000626:Aminopeptidases / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D000818:Animals; D005614:Freeze Fracturing; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000201:enzymology / Q000648:ultrastructure*; D007672:Kidney Cortex / Q000201:enzymology / Q000648:ultrastructure*; D007687:Kidney Tubules, Proximal / Q000648:ultrastructure; D008854:Microscopy, Electron; D008871:Microvilli / Q000648:ultrastructure; D011092:Polyethylene Glycols / Q000494:pharmacology; D051381:Rats
chemical_list: D011092:Polyethylene Glycols; D000626:Aminopeptidases; D000409:Alanine