Platelet Adhesion and Aggregation Responses in Hypertension

Platelet adhesion, as an indicator of platelet responsiveness, has been measured for over fifty years (26). In 1968 Poplawski et al. (1) were the first to report that platelet 

These authors have demonstrated that plasma levels of P-thromboglobulin and soluble P-selectin, two markers of platelet activation, are elevated in hypertensive patients. 

However, increased platelet aggregation response in SHR has not been found to be universal. In our laboratory, under identical experimental conditions utilizing the same washed platelet samples at the same time, we have observed that while fiuombin induces a greater platelet aggregation response in SHR, ADP induces a lesser fibrinogen binding 

l Cytosolic calcium levels and platelet reactivity in hypertension 

Free cytosolic calcium has been shown to play an important role in the regulation of cellular processes in a variety of cells including platelets (44). Free cytosolic calcium concentration in unstimulated platelets is maintained by a number of mechanisms which control the influx of extracelli calcium ions, the release of calcium ions fi om storage sites within platelets as well as the removal of ionized calcium fi m cytosol (44). Platelets 

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