Previous studies in rats demonstrated that orally administered, unfractionated bovine lung
heparin is absorbed and has a dose-dependent antithrombotic effect. The objective of this study was to determine if an oral
low molecular weight heparin had a similar antithrombotic effect in the same model.
Thrombosis was induced in rats by application of 10%
formalin in 65%
methanol to the exposed jugular vein. Immediately following, saline,
unfractionated heparin (3.3-60 mg/kg) or the
low molecular weight heparin,
Logiparin (0.025-15 mg/kg; 20-30 rats per group) was placed in the stomach and 4 h later the jugular vein was inspected for a
thrombus. Compared to saline, oral
Logiparin reduced the incidence of
thrombosis at all doses with a dose-dependent effect suggested. A significant increase was observed in the activated partial thromboplastin time and in plasma
heparin concentrations, determined by Accuclot Heptest and anti-
factor Xa chromogenic assay for rats given oral
Logiparin versus saline. A dose-dependent increase in plasma
heparin concentration was observed when estimated by the anti-Xa chromogenic assay.
Heparin was recovered in 9% of aortic endothelial samples when > or = 0.8 mg/kg
Logiparin was administered. A 50% reduction in
thrombosis was observed at 0.1 mg/kg for oral
Logiparin versus 7.5 mg/kg for unfractionated bovine lung
heparin indicating that oral
Logiparin is an effective
antithrombotic agent at doses lower than
unfractionated heparin. Orally administered
low molecular weight heparin may be useful for the prevention and treatment of
thrombosis.