Aggregation of human platelets in an annular vortex distal to a tubular expansion

摘要: The aggregation of human platelets was studied in an annular vortex formed downstream sudden expansions having a diameter ratio, outer to inner tube, 3.33. Platelet-rich plasma (PRP), washed Tyrodes-albumin, as well whole blood were investigated. In the smallest expansion 151- into 504-μm frequent interactions and collisions between circulating cells seen result formation growth aggregates which migrated center trapped. measured rate extent greater heparinized than citrated PRP, lowest platelet suspensions. These differences paralleled by similar ADP- or thrombin-induced reaction aggregometer. given suspension steady flow, observed only narrow range Reynolds number 4.5 17 markedly increased addition subthreshold amounts ADP thrombin. pulsatile there significant decrease size formed—from > 100 40 μm diameter, if already present suspension, trapped vortex. results have demonstrated for first time that within shear stress vortex, can aggregate without any agents.