Abstract
In order to elucidate some relationships between platelets and vessel wall injury, we have studied platelet kinetics of spontaneously hypertensive rats (SHR) and also have localized the released substances of platelet granules in human intact platelets and platelets interacting with the subendothelium of rabbit aorta in vitro.
The increased platelet production and shortened platelet survival time were observed in SHR stroke-prone (SHRSP) after 10 weeks of age. These accelerated platelet kinetics were suppressed by administration of anti-platelet drug and vitamin E. These data suggested the increased platetet consumption was brought about by vascular alteration in SHRSP.
Using immunoperoxidase staining, we have localized the platelet factor 4, fibronectin, fibrinogen and factor VIII antigen in α-granules of human platelets. During human platelet adhesion and aggregation on the subendothelium of rabbit aorta in vitro, these released substances were localized between aggregated platelets and subendothelium as well as in adherent platelets. These antigen were also observed in vessel wall under the internal elastic lamina. During the interaction of the platelets to subendothelium of vessel wall, released substances from platelet may permeate across the internal elastic lamina of vessel wall.
