Summary
We evaluated the antithrombotic effects of DX-9065a, a specific factor Xa inhibitor,
using tissue thromboplastin-induced DIC (TP-DIC) and the arterio-venous shunt (AV
shunt) in rats. Intravenous TP injection reduced the platelet counts and fibrinogen
concentrations in blood. In the TP-DIC model, an intravenous dose of DX-9065a 0.23
mg/kg 1 min before TP injection suppressed the consumption of platelets and fibrinogen
to 57% and 66%, respectively, and the production of FDP almost completely. In the
AV shunt model, DX-9065a inhibited thrombus formation to 51% on intravenous administration
of 0.23 mg/kg and to 60% when given orally at 23.3 mg/kg. Intravenous administration
of 2.33 mg/kg of DX-9065a did not affect the bleeding time. These results suggest
that Xa inhibition may be an appropriate approach for suppressing thrombosis without
impairing haemostasis.
