AJP - Cell Physiology, Vol 260, Issue 5 C965-C974, Copyright © 1991 by American Physiological Society
Antibody-detectable changes in fibrinogen adsorption affecting platelet activation on polymer surfaces
E. Shiba, J. N. Lindon, L. Kushner, G. R. Matsueda, J. Hawiger, M. Kloczewiak, B. Kudryk and E. W. Salzman
Beth Israel Hospital, Boston 02215.
Reactivity of platelets with an artificial surface exposed to whole blood
is correlated with the concentration of adsorbed fibrinogen detectable by
antifibrinogen antibodies. To examine the effect on platelets of the
organization (distribution, orientation, conformation) of fibrinogen
adsorbed on a hydrophobic surface, we studied the binding of polyclonal and
monoclonal antifibrinogen antibodies to polyalkyl methacrylate polymers
previously exposed to purified fibrinogen solution or diluted plasma and
compared the results with platelet retention in methacrylate bead columns.
There was an increase in platelet retention following diluted plasma
pretreatment, which was eliminated by a polyclonal antibody against
fibrinogen or against a gamma-(395-411) peptide from fibrinogen and was
reduced by monoclonal antibodies (4A5, 4-2) against other COOH-terminal
gamma-chain epitopes. Monoclonal antibody 10E5 against the fibrinogen
receptor GpIIb/IIIa totally inhibited platelet retention in the bead
columns. Our data suggest that different methacrylate polymers induce
different changes in adsorbed fibrinogen, which may interfere with its
interaction with platelets, and that platelet retention in a methacrylate
bead column involves interaction of the COOH-terminal end of the
gamma-chain of adsorbed fibrinogen with platelet GpIIb/IIIa receptors.
