Studies of Platelet Adhesiveness to Collagen Fibers

Platelet adhesiveness is generally measured by a glass-beads column method (GBC method), as other available methods using collagen and subendothelium are too complex for clinical use.We have studied a new method of measuring platelet adhesiveness to collagen fibers supported on sepharose (CS method).The results of fundamental st udies on platelet adhesiveness using CS method were as follows:1. W ith increasing collagen concentration, platelet adhesiveness increased.2. Platelet adhesiveness was not change at a stirring speed of 150 to 15,00 rpm and at a stirring time of over one minitue.3. Platelet adhesivenes s was not change in the presence of above 0.5 mM EDTA which inhibited platelet aggregation.4. The influen ce of the platelet count at 10-40×104/μl on the platelet adhesiveness did not observed, but at above 60×104/μl, platelet adhesiveness slightly decreased.5. After storage for 72 hr at room temperature, platelet adhesiv eness to collagen was slightly decreased and markedly decreased (below 50% of control values) after 7 days.6. Platelets adhered normally to collagen fibers without extracellular von Willeb rand factor and divalent cations, and by pretreatment of platelets with neuraminidase reducing platelet surface negative charge.7. The data o btained with the GBC and CS methods in healthy adults correlated signif i cantly. This CS method is simpler than other methods employing collagen and closer to in vivo conditions than the GBC method. Thease results suggeste d that the mechanism of platelet adhesiveness to collagen fibers differ from that of adhesion to glass.