[Effects of low doses of activated protein C in experimental arterial thrombosis in rats]

Activated C protein (ACP) is a physiological anticoagulant enzyme that is capable to inactivate factors Va and VIIIa, thereby having a wide spectrum of antithrombotic effects. Low-dose ACP was tested for its ability to affect anodic current-induced arterial thrombosis in the rat. ACP given in low doses (15 micrograms/kg, 7% of total C protein in the rat) was found to produce a marked antithrombotic effect. With this, the activated partial thromboplastin time remained virtually unchanged, and its antithrombotic action was equal to that of heparin administered in a dose of 125 U/kg. In the authors' opinion, ACP may form the basis for designing a highly effective antithrombotic agent.