title: Technetium-99m labeled 50H.19 antibody fragments: interaction of the antibody with platelets.
abstract: The monoclonal antibody 50H.19 recognized three antigens (Mr = 31-, 40-, 45-K) on normal and thromboasthenic platelets, but only one (Mr = 31-K) on Bernard-Soulier platelets. The intact antibody and its F(ab')2 fragments, had direct platelet-aggregating activity, and induced the platelet release reaction. The intact antibody potentiated platelet aggregation induced by platelet-activating factor or thrombin. Additions of indomethacin did not inhibit aggregation: addition of PGI2, or a calcium channel blocker completely inhibited aggregation. A reduced amount of platelet-aggregating activity was observed with antibody fragments prepared for labeling with 99mTc by pre-exposure to stannous ions, and herein used in biodistribution studies and elsewhere in thrombus imagining studies (J. Nucl. Med. 27: 1315; 1986). Antibody fragments radiolabeled with 99mTc bound to isolated platelets and to clots containing platelets.
authors.affiliation: University of California, San Francisco, Veterans Administration Medical Center 94121.
authors.forename: F H
authors.initials: FH
authors.lastname: Valone
authors.forename: R B
authors.initials: RB
authors.lastname: Stricker
authors.forename: P O
authors.initials: PO
authors.lastname: Zamora
authors.forename: V O
authors.initials: VO
authors.lastname: Shah
authors.forename: P L
authors.initials: PL
authors.lastname: Mann
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D000941:Antigens / Q000032:analysis; D001606:Bernard-Soulier Syndrome / Q000097:blood; D001792:Blood Platelets / Q000276:immunology*; D006801:Humans; D007128:Immunoglobulin Fragments / Q000276:immunology; D066298:In Vitro Techniques; D010974:Platelet Aggregation; D013667:Technetium; D013915:Thrombasthenia / Q000097:blood; D014018:Tissue Distribution
chemical_list: D000911:Antibodies, Monoclonal; D000941:Antigens; D007128:Immunoglobulin Fragments; D013667:Technetium