title: Immunoreactivity to a monoclonal antibody (OS-3) is shared by osteoclasts and bicarbonate-secreting cells.
abstract: OS-3, a monoclonal antibody raised against macrophagic cells derived from cultured rat glomeruli, reacts with the plasma membrane of various bicarbonate-secreting cells such as epithelial cells of the pancreatic excretory duct and type B intercalated cells of the kidney, suggesting that the antigenic molecule of OS-3 is involved in bicarbonate production and/or secretion. Since osteoclasts must vigorously extrude bicarbonate to maintain cytoplasmic pH in a physiologic range during proton secretion, we examined the localization of OS-3 immunoreactivity in the bone tissue to determine the involvement of the detected molecule in the transmembrane transport of bicarbonate in osteoclasts. The OS-3 selectively stained the basolateral plasma membrane of osteoclasts. Ultrastructurally, the immunoreactivity with OS-3 was associated with small cytoplasmic projections and microplicae of the basolateral plasma membrane. This finding suggests that osteoclasts express the molecule common to bicarbonate-secreting cells to utilize it for bicarbonate transport during bone resorption.
authors.affiliation: Department of Oral Anatomy, Health Sciences University of Hokkaido School of Dentistry, Ishikari-Tobetsu, Japan. irie@hoku-iryo-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Irie
authors.forename: M
authors.initials: M
authors.lastname: Orikasa
authors.forename: Y
authors.initials: Y
authors.lastname: Sakakura
authors.forename: E
authors.initials: E
authors.lastname: Tsuruga
authors.forename: T
authors.initials: T
authors.lastname: Iwanaga
authors.forename: T
authors.initials: T
authors.lastname: Yajima
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism*; D001639:Bicarbonates / Q000276:immunology*; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D004848:Epithelium / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D007678:Kidney Glomerulus / Q000166:cytology / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D016253:Microscopy, Immunoelectron; D008954:Models, Biological; D010010:Osteoclasts / Q000276:immunology*; D010183:Pancreatic Ducts / Q000378:metabolism; D011522:Protons; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000911:Antibodies, Monoclonal; D001639:Bicarbonates; D011522:Protons