Effects of Plasma Components on Platelet Adhesion to Microcapsules

抄録

Adhesion of rabbit platelets to microcapsules having different numbers of carboxyl groups was examined. The platelets adhered more easily to microcapsules having higher negative charges than to those having lower ones. It was strongly suggested that this trend was caused by plasma components adsorbed on the microcapsules ; the difference in surface negative charge caused a difference in adsorption of plasma components, which would in turn result in the difference in platelet adhesion. Among various plasma components, the major proteins, albumin, γ-globulin and fibrinogen, were all found to inhibit platelet adhesion to the microcapsules, while fresh rabbit serum facilitated it, irrespective of surface negative charge. On the other hand, heat-inactivated rabbit serum was found to inhibit platelet adhesion almost completely. These findings led us to conclude that certain complement adsorbed on the microcapsule surface facilitate platelet adhesion, and the difference in platelet adhesion, which is dependent on the surface negative charge of the microcapsules in the presence of plasma, can be explained in terms of competitive adsorption of the complement and fibrinogen.