Effects of Aspirin on Thrombin Generation To the Editor: Michelson et al1 recently reported differences in platelet glycoprotein IIb/IIIa function in relation to the common Pl polymorphism. Pl-positive platelets showed a lower threshold for activation. This was supported by the gene dosage effect: P1 homozygotes had the highest activation of their platelets using a range of ADP concentrations. ...

We report that a genetic polymorphism of the alpha2-adrenergic receptor (A2AR) encoded by chromosome 10 is associated with hypertension and an increase in epinephrine-mediated platelet aggregation in humans. The mechanism responsible for this heritable contrast in sensitivity to epinephrine is unknown. We tested our hypothesis that epinephrine-induced platelet aggregation is mediated by activat...

Shear-induced platelet aggregation is important in physiological hemostasis and in the pathogenesis of arterial thrombosis. It requires extracellular Ca2+, platelet membrane glycoproteins Ib/IX and IIb/IIIa, von Willebrand factor (vWF), and ADP. We studied the effects of desmopressin (DDAVP), which increases plasma vWF levels and shortens the bleeding time, and of ticlopidine, which inhibits pl...

Coagulation and platelet function studies were performed on 24 normal subjects and 29 patients with chronic renal failure due to various causes. Thrombocytopenia was uncommon in the uraemic patients but there was reduced platelet retention in glass bead columns and platelet aggregation with adenosine diphosphate (ADP) and thrombin was slower and less complete than normal. The rate of platelet d...

Effects of Aspirin on Thrombin Generation To the Editor: Michelson et al1 recently reported differences in platelet glycoprotein IIb/IIIa function in relation to the common Pl polymorphism. Pl-positive platelets showed a lower threshold for activation. This was supported by the gene dosage effect: P1 homozygotes had the highest activation of their platelets using a range of ADP concentrations. ...

The aim of this study was to explore the effects of S-nitrosoglutathione (GSNO) on the aggregation of frozen platelets, the platelet nitric oxide (NO) content and the expression of membrane glycoproteins. The level of frozen platelet aggregation was measured using a platelet aggregation analyzer, while the content of NO was measured by the nitrate reductase method and the expression of frozen p...

The effect of a human fibrinogen preparation on in vitro platelet aggregation was assessed. Platelets were obtained from healthy volunteers. Human fibrinogen induced platelet aggregation in 65% of platelet rich plasma samples and enhanced submaximal platelet aggregation induced by heparin or by several conventional agonists in all samples. Aggregation induced by fibrinogen alone was reversed by...

Effects of Aspirin on Thrombin Generation To the Editor: Michelson et al1 recently reported differences in platelet glycoprotein IIb/IIIa function in relation to the common Pl polymorphism. Pl-positive platelets showed a lower threshold for activation. This was supported by the gene dosage effect: P1 homozygotes had the highest activation of their platelets using a range of ADP concentrations. ...