Abstract
Protamine sulfate (Protamine) has been used for the neutralization of over-doses of heparin in order to avoid bleeding.
In the present study, we examined the neutralization of low molecular weight heparin, FR-860, by protamine and compared the results with those of Novo heaprin (heparin).
The prolongation of aPTT and thrombin time induced by FR-860 was immediately neutralized by protamine in in vivo model of rabbits. Whereas, anti-Xa activity and the prolongation of Xa clotting time induced by FR-860 were resistant to the neutralization by protamine. The prolongation of aPTT, thrombin time and Xa clotting time and anti-Xa activity induced by heparin were completely neutralized by protamine.
In vitro study, anti-thrombin activity of heparin was completely neutralized in parallel with the anti-Xa activity by protamine. The anti-thrombin activity of FR-860 was also completely neutralized in a way similar to that of heparin, whereas the anti-Xa activity was resistant to the netralization by protamine.
These results suggest that the bleeding tendency caused by over-doses of low molecular weight haparin can be specifically prevented by protamine.
