An investigation of fibrin-platelet adhesive interactions by microfluorimetry.
Interactions between human blood platelets and fibrin have been visualized by light microscopy, and quantitative details of the extent, rate and specificity of fibrin-platelet binding obtained by microfluorimetry. Adhesion of fluorescein-labelled fibrin to activated platelets yielded brightly fluorescent fibrin-platelet aggregates, which emitted light at an intensity 4-7-fold greater than that due to nonspecific association of fluorescein-fibrin with unstimulated fixed cells. The intensity of fluorescent light emitted from fibrin-platelet aggregates increased as a function of time, reaching a plateau after about 1 h under physiological buffer and temperature conditions. Two monoclonal antibodies directed against the glycoprotein IIb-IIIa complex, which have been shown to inhibit the binding of fibrinogen and soluble fibrin oligomers to ADP-stimulated platelets, were employed to further probe the specificity of this adhesive interaction. In contrast to the results with the soluble ligands, one of these antibodies (HP1-1D) was capable of fully inhibiting the attachment of fluorescent fibrin to ADP-activated cells while the other (AP-2) was much less effective.
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D000911:Antibodies, Monoclonal; D012103:Batroxobin / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D005337:Fibrin / Q000378:metabolism*; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006801:Humans; D007158:Immunologic Techniques; D007700:Kinetics; D008856:Microscopy, Fluorescence; D010974:Platelet Aggregation; D010980:Platelet Membrane Glycoproteins / Q000276:immunology / Q000502:physiology; D013861:Thiocyanates
D000911:Antibodies, Monoclonal; D005452:Fluoresceins; D005456:Fluorescent Dyes; D010980:Platelet Membrane Glycoproteins; D013861:Thiocyanates; D000244:Adenosine Diphosphate; D005337:Fibrin; D012103:Batroxobin; D016650:Fluorescein-5-isothiocyanate