DECREASED ADHESION OF OXIDIZED LDL-STIMULATED PLATELETS CAUSED BY CYTOCHALASIN-D

The adhesion of human blood platelets is studied with an in vitro mode l using reflection contrast microscopy and an image analysis system. T he adhesive feature is promoted by oxidatively modified low density li poprotein, which also induces functional morphological changes of plat elets. However, when washed platelets are pretreated with 0.05 mM cyto chalasin D, oxidized low density lipoprotein (100 mu g/ml) causes a sl ower increase of the adhesion area (11.6 mu m(2)/min) compared to untr eated platelets (15.7 mu m(2)/min) or platelets treated by oxidized lo w density lipoprotein alone (20.5 mu m(2)/min, P<0.01). These results are supported by light transmission analysis and by transmission elect ron microscopy. Our experiments suggest that cytochalasin D inhibits t he change of platelets in shape induced by oxidized low density lipopr otein, hinders the adhesion, but does not prevent the adhesion entirel y.