title: Monoclonal antibody to the gastrin receptor on parietal cells recognizes a 78-kDa protein.
abstract: Four monoclonal antibodies reactive by immunofluorescence and by flow microfluorimetry with canine and porcine gastric parietal cell membranes were produced by fusion of mouse NS-1 myeloma cells with splenocytes from mice immunized with a population of canine gastric mucosal cells containing 60-70% parietal cells. One of these, an IgM antibody designated 2C1, reacted with the surface membranes of parietal cells by immunofluorescence, flow microfluorimetry, and immunogold electron microscopy; competed with 125I-labeled gastrin for binding to gastric cells; and inhibited by 56% maximal gastrin stimulation of [14C]aminopyrine uptake in parietal cells. The antibody immunoprecipitated 125I-labeled samples of a 78-kDa gastrin-binding protein purified from membrane extracts of porcine gastrin mucosa but did not recognize the same protein labeled covalently with 125I-labeled gastrin-(2-17)-hexadecapeptide. These observations suggest that the previously identified 78-kDa gastrin-binding protein is the gastrin receptor and that the antibody 2C1 is directed against the gastrin binding site of the gastrin receptor.
mesh_terms: D000632:Aminopyrine / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal; D002462:Cell Membrane / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005755:Gastrins / Q000378:metabolism; D006632:Histamine / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D011949:Receptors, Cholecystokinin / Q000032:analysis*; D013552:Swine
chemical_list: D000911:Antibodies, Monoclonal; D005755:Gastrins; D011949:Receptors, Cholecystokinin; D000632:Aminopyrine; D006632:Histamine