Fibronectin and the multiple interaction model for platelet-collagen adhesion.

Abstract

A rapid, sensitive and reproducible assay to determine the adhesion of platelets to collagen was developed. Collagen fibers and adherent platelets were retained on polycarbonate membrane filters. Chemical modification of collagen by acetylation and of platelets by treatment with chymotrypsin markedly reduced adhesion. The role of fibronectin in the collagen-platelet interaction was examined. Treatment of platelets with purified antibody or Fab'' fragments to fibronectin only slightly reduced adhesion. Preincubation of platelets with high concentrations of gelatin reduced adhesion by only 22% but failed to inhibit aggregation. Fibronectin has only a limited role platelets-collagen adhesion and is not involved in the adhesion that leads to aggregation or is only 1 of several adhesion mechanisms, any of which alone can initiate aggregation.