title: The anatomy of bone sialoprotein immunoreactive sites in bone as revealed by combined ultrastructural histochemistry and immunohistochemistry.
abstract: Bone sialoprotein was immunolocalized at the EM level in thin Lowicryl K4M sections of rat bone. Because of the unconventional EM morphology of the bone matrix seen in thin demineralized acrylate sections, the pattern of immunolabeling was compared with detailed structural images of demineralized bone obtained using an en bloc treatment of tissue samples with the cationic electron 'dye,' Malachite Green (MG), which provides stabilization and retention of anionic material throughout specimen processing. A system of structures corresponding to the sites of bone sialoprotein (BSP) immunoreactivity, as seen in Lowicryl K4M this sections, could be readily identified in the MG-treated, epoxy thing sections. This system includes the cement lines, and aggregates of similar material within mineralized bone and mineralizing osteoid. The virtual identity of BSP distribution with the arrangement of the MG-visualized material indicates that a BSP-enriched, noncollagenous phase can be demonstrated using different, unrelated tissue preparation and imaging protocols for EM. Besides improving our understanding of the distribution of bone sialoprotein in bone, these data assign a previously unrecognized structural dimension to noncollagenous material in the bone matrix.
authors.affiliation: Department of Experimental Medicine, La Sapienza University, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Riminucci
authors.forename: G
authors.initials: G
authors.lastname: Silvestrini
authors.forename: E
authors.initials: E
authors.lastname: Bonucci
authors.forename: L W
authors.initials: LW
authors.lastname: Fisher
authors.forename: P
authors.initials: P
authors.lastname: Gehron Robey
authors.forename: P
authors.initials: P
authors.lastname: Bianco
mesh_terms: D000818:Animals; D018775:Bone Demineralization Technique; D001857:Bone Matrix / Q000737:chemistry* / Q000648:ultrastructure; D001842:Bone and Bones / Q000737:chemistry* / Q000196:embryology / Q000648:ultrastructure; D002113:Calcification, Physiologic; D005260:Female; D006651:Histocytochemistry; D007150:Immunohistochemistry; D058574:Integrin-Binding Sialoprotein; D016253:Microscopy, Immunoelectron; D011247:Pregnancy; D051381:Rats; D012795:Sialoglycoproteins / Q000032:analysis* / Q000276:immunology; D013977:Tibia
chemical_list: C546873:Ibsp protein, rat; D058574:Integrin-Binding Sialoprotein; D012795:Sialoglycoproteins