Fibronectin-mediated inhibition of human platelet activation by crosslinked immunoglobulin G.
The effect of purified human plasma fibronectin on stimulation of human platelets with crosslinked immunoglobulin G (IgG) was tested by means of aggregometry, 14C-serotonin release and fibronectin-to-platelet binding experiments. Incremental additions of fibronectin to gel-filtered platelets (8 X 10(8)/ml) followed by 25 micrograms/ml bisdiazoniumbenzidine (BDB)-crosslinked IgG produced a dose-related inhibition of platelet aggregation and suppression of 14C-serotonin release from the platelets. Evidence was obtained that upon stimulation of the platelets with BDB-IgG, fibronectin becomes bound to its receptor and that further platelet activation is inhibited when a sufficient number of receptors is occupied.
D001560:Benzidines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005353:Fibronectins / Q000494:pharmacology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D066298:In Vitro Techniques; D010974:Platelet Aggregation / Q000187:drug effects*; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic / Q000378:metabolism; D012701:Serotonin / Q000097:blood; D013997:Time Factors
D001560:Benzidines; D005353:Fibronectins; D007074:Immunoglobulin G; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic; D012701:Serotonin; C006770:bis(diazo)benzidine