title: Comparison of three independent methods as estimates of platelet inhibition after a single dose of acetylsalicylic acid.
abstract: In order to assess the ability of three different (one in vivo, one ex vivo and one in vitro) methods to estimate platelet function, 10 healthy volunteers were given a single oral dose of 160 mg ASA. Platelet function was assessed before, 4, 24, 48 and 72 h after dosing by urinary excretion of thromboxane B2, filtragometry and collagen-based whole blood aggregometry. Further, in order to study mechanisms for platelet aggregation in filtragometry, platelet activation was assessed by measurements of beta-thromboglobulin at three different places within the filtragometer test unit in another nine healthy subjects. Four hours after ASA, the aggregation time during filtragometry increased by 213 +/- 133% (p < 0.001) and was parallelled by a decrease in impedance 85 +/- 7% (p < 0.001) indicating an inhibition of platelet aggregability in both tests. A subsequent gradual recovery was observed with both methods. The excretion of thromboxane B2 followed the aggregability pattern being maximally reduced by 72 +/- 6% (p < 0.01) 24 h after ASA and then gradually recovering. All three methods indicated that platelet function was still decreased 72 h after dosing. The urinary excretion of prostacyclin did not change significantly. The results of filtragometry and impedance aggregometry correlated to the logarithm of thromboxane B2 excretion (r = 0.60; p < 0.01 and r = 0.49; p < 0.01, respectively) and to each other (r = 0.70; p < 0.001). In filtragometry beta-thromboglobulin increased significantly (p < 0.05) over the filter.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, Huddinge Hospital, Sweden.
authors.forename: K E
authors.initials: KE
authors.lastname: Karlberg
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: N
authors.initials: N
authors.lastname: Egberg
authors.forename: J
authors.initials: J
authors.lastname: Nowak
authors.forename: C
authors.initials: C
authors.lastname: Sylvén
mesh_terms: D001241:Aspirin / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D013997:Time Factors; D001620:beta-Thromboglobulin / Q000032:analysis
chemical_list: D001620:beta-Thromboglobulin; D001241:Aspirin