title: IgM-Fc receptor-mediated phagocytosis of rat macrophages.
abstract: The features and function of IgM-FcR of rat peritoneal macrophages were studied. Macrophages specifically bind and phagocytose ox red blood cells coated with rat IgM (EA-IgM) through a specific receptor. This receptor is trypsin sensitive and its activity requires Ca++ ions. Both sodium azide and low temperature (4 degrees) inhibit the bindings as well as ingestion of EA-IgM by macrophages, suggesting the metabolically dependent character of the interaction between EA-IgM and macrophages. Colchicine inhibits the binding of EA-IgM by macrophages. Similarly, the ingestion of EA-IgM was also inhibited when peritoneal exudate cells (PEC) were pre-treated with colchicine or vinblastine or cytochalasin B. It is suggested that cytoskeletal elements of macrophages play an important role both in the binding of EA-IgM to their receptors and in the subsequent internalization of the receptor-ligand complexes. Ingestion of soluble IgM antibodies containing immune complexes (IC) resulted in a release of beta-glucuronidase from macrophages.
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex / Q000276:immunology; D001202:Ascitic Fluid / Q000166:cytology; D002118:Calcium / Q000276:immunology; D002478:Cells, Cultured; D005966:Glucuronidase / Q000378:metabolism; D007075:Immunoglobulin M / Q000276:immunology*; D008264:Macrophages / Q000201:enzymology / Q000276:immunology*; D010587:Phagocytosis / Q000187:drug effects; D051381:Rats; D011961:Receptors, Fc / Q000276:immunology*; D012397:Rosette Formation; D013696:Temperature; D014357:Trypsin
chemical_list: D000936:Antigen-Antibody Complex; D007075:Immunoglobulin M; D011961:Receptors, Fc; D005966:Glucuronidase; D014357:Trypsin; D002118:Calcium