Murine model of ferric chloride‐induced vena cava thrombosis: evidence for effect of potato carboxypeptidase inhibitor

Abstract

Summary. Background/objective: Thrombin-activatable fibrinolysis inhibitor (TAFI) is a plasma carboxypeptidase that renders a fibrin-containing thrombus less sensitive to lysis. In the present study, we describe the development of a murine model of vena cava thrombosis and its use to characterize the antithrombotic activity of potato carboxypeptidase inhibitor (PCI) of TAFIa (activated TAFI) in mice. Methods/results: Vena cava thrombosis was induced by various concentrations of FeCl 3 in C57BL/6 mice. A relatively mild stimulus (3.5% FeCl 3 ) induced thrombosis that was consistent and sensitive to reference antithrombotic agents such as clopidogrel and heparin. Dose-response studies identified a PCI dose (5 mg kg )1 bolus plus 5 mg kg, i.v.) that produced a maximum 45% decrease in vena cava thrombus mass as assessed by protein content (n ¼ 8, P < 0.01 compared to vehicle) in the 3.5% FeCl 3 -induced model without exogenous tissue plasminogen activator administration. In contrast, PCI had no effect on 3.5% FeCl 3 -induced carotid artery thrombosis in mice. In a tail transection bleeding model, the 5 mg kg )1 bolus plus 5 mg kg )1 h )1 dose of PCI increased tail-bleeding time up to 3.5 times control (n ¼ 8, P < 0.05). The ex vivo activity of antithrombotic doses of PCI was also demonstrated by the enhanced lysis of whole blood clots formed in a thrombelastograph with the addition of a sub-threshold concentration of tPA. Conclusion: These studies provide evidence for a role of TAFIa in venous thrombosis in mice, and describe an optimized vena cava injury model appropriate for the evaluation of antithrombotic drugs and the characterization of novel therapeutic targets.

Thrombin-Activatable Fibrinolysis Inhibitor Is Activated in an Instant Blood-Mediated Inflammatory Reaction After Intraportal Islet Transplant

“…[20][21][22][23] Additionally, inhibition of TAFIa represents a potentially subtle adjustment of the clotting and lysis balance, without affecting the coagulation cascade. Ideally, this subtlety may reduce the risk of bleeding when using TAFIa inhibitor, compared with other potential mechanism for treating thrombotic disease.…”

Platelet P2Y 12 Receptor Influences the Vessel Wall Response to Arterial Injury and Thrombosis

“…19 Clopidogrel has been found previously to inhibit thrombus formation in a murine FeCl 3 injury model. 25 Wild-type mice were administered clopidogrel, the active metabolite of which acts as an antagonist at the P2Y 12 receptor. After FeCl 3 injury, a significantly reduced neointimal response was observed at 21 days in treated wild-type animals compared with wild-type mice that were not administered clopidogrel.…”

ACE2 Activation Promotes Antithrombotic Activity

“…Thrombus formation was induced in the abdominal vena cava of SHR and WKY using a ferric chloride (FeCl 3 ) solution, as described elsewhere (10). Briefly, after anesthesia (ketamine, xylazine and acepromazine at 30, 6, and 1 mg/kg, respectively), the jugular vein was cannulated for drug administration.…”