Summary Endothelium provides the physiologic nonthrombogenic surface in vivo. Connective tissue components underneath the endothelial lining form the subendo‐thelium. The subendothelial surface appears far less thrombogenic than collagen fibers. Platelet adhesion to subendothelium as an entity is greatly enhanced by the presence of other blood cells, by an increase in the flow rate of the circulating blood, and by the presence of divalent cations. The affinity of platelets to different connective tissue components of the subendothelium varies markedly. When exposed to the same blood stream in a newly developed perfusion chamber, the affinity of platelets to the respective material decreases in the following order: collagen fibers, amorphous material (basement membrane), microfibrils, and elastin.
Baumgartner et al. (1972) studied this question.