Induction of marked thrombin activity by pharmacologic concentrations of plasminogen activators in nonanticoagulated whole blood.
Abstract
Thrombin activity reflected by increased plasma concentrations in vivo of fibrinopeptide A (FPA) increases when streptokinase (SK) is administered to patients with acute myocardial infarction. Although procoagulant effects have been found in vitro, the use of anticoagulated plasma limits the extent to which the phenomena observed can be viewed to implicate procoagulant effects in vivo. Accordingly, we characterized the procoagulant effects of SK and tissue plasminogen activator (t-PA) in nonanticoagulated whole blood. Blood was collected from normal volunteers by venipuncture (No. 19 gauge steel needle) directly into polypropylene tubes containing either t-PA, SK, SK and heparin, t-PA and heparin, or saline. The concentration of FPA after 10 min of incubation with saline was 150 +/- 46 nM (n = 14)(SE). In contrast, in blood incubated with SK FPA was consistently and markedly increased after 10 min: 2318 +/- 416 nM (100 IU/ml SK) and 10,889 +/- 1156 nM (1000 IU/ml SK) (p less than 0.001 compared with control). Less marked elevations of FPA occurred after 10 min in blood incubated with t-PA (3171 +/- 604 nM with 2500 ng/ml t-PA, p less than 0.01 compared with 1000 IU/ml SK). Increases in FPA were less than 100 nM in blood incubat...Continue Reading
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Blood Clotting Disorders
Thrombophilia includes conditions with increased tendency for excessive blood clotting. Blood clotting occurs when the body has insufficient amounts of specialized proteins that make blood clot and stop bleeding. Here is the latest research on blood clotting disorders.