Platelet adherence to subendothelium of human arteries in pulsatile and steady flow

Abstract

Platelet adherence to human artery subendothelium was investigated in pulsatile and steady flow in an annular perfusion chamber. The platelet adhesion was larger in steady flow than in pulsatile flow. The ratio of contact platelets to spread platelets was higher in pulsatile flow. The number of adherent platelets increased at increasing platelet number, red cell concentration, perfusion time, and flow velocity in both systems. The difference in platelet adherence in the two flow systems decreased at increasing adhesion, indicating that saturation occurred. The experiments indicate that for comparative studies of platelet adhesion in steady flow at a physiological red cell concentration and a shear rate as observed in small arteries, it is preferable to apply subnormal platelet counts and perfusion times shorter than 5 min.