title: Interactions of staphylokinase with human platelets.
abstract: The interactions of recombinant staphylokinase (SakSTAR) with human platelets were investigated in a buffer milieu, in a human plasma milieu in vitro, and in plasma from patients with acute myocardial infarction (AMI) treated with SakSTAR. In a buffer milieu, the activation rate of plasminogen by SakSTAR or streptokinase (SK) was not significantly altered by addition of platelets. Specific binding of SakSTAR or SK to either resting or thrombin-activated platelets was very low. ADP-induced or collagen-induced platelet aggregation in platelet-rich plasma (PRP) was 94 +/- 2.7% or 101 +/- 1.7% of control in the presence of 0.1 to 20 microM SakSTAR, with corresponding values of 95 +/- 2.8% or 90 +/- 4.6% of control in the presence of 0.1 to 4 microM SK. No effects were observed on platelet disaggregation. ATP secretion following collagen-induced platelet aggregation was 4.3 +/- 0.26 microM for SakSTAR (at concentrations of 0.1 to 20 microM) and 4.4 +/- 0.35 microM for SK (at concentrations of 0.1 to 4 microM), as compared to 3.4 +/- 0.70 microM in the absence of plasminogen activator. Fifty % lysis in 2 h (C50) of 60 microliters 125I-fibrin labeled platelet-poor plasma (PPP) clots prepared from normal plasma or from plasma of patients with Glanzmann thrombasthenia and immersed in 0.5 ml normal plasma, was obtained with 12 or 16 nM SakSTAR and with 49 or 40 nM SK, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Center for Molecular and Vascular Biology, University of Leuven, Belgium.
authors.forename: H R
authors.initials: HR
authors.lastname: Lijnen
authors.forename: B
authors.initials: B
authors.lastname: Van Hoef
authors.forename: D
authors.initials: D
authors.lastname: Collen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D002863:Chromogenic Compounds; D003018:Clot Retraction; D003094:Collagen / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005342:Fibrinolysis / Q000187:drug effects; D006801:Humans; D008666:Metalloendopeptidases / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D008969:Molecular Sequence Data; D009203:Myocardial Infarction / Q000097:blood / Q000628:therapy; D010958:Plasminogen / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects; D011485:Protein Binding; D011994:Recombinant Proteins / Q000627:therapeutic use; D013300:Streptokinase / Q000494:pharmacology / Q000627:therapeutic use; D013915:Thrombasthenia / Q000097:blood; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use
chemical_list: D002863:Chromogenic Compounds; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate; D010958:Plasminogen; D003094:Collagen; D013300:Streptokinase; D010959:Tissue Plasminogen Activator; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus