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


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(-1) h(-1), i.v.) that produced a maximum 45% decrease in vena cava thrombus mass as assessed by protein content (n = 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 = 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.


CONCLUSIONS
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.
Wang
X
X
Department of Thrombosis Biology, Bristol Myers Squibb Company, Pennington, NJ 08534, USA. xinkang.wang@bms.com
Smith
P L
PL
Hsu
M-Y
MY
Ogletree
M L
ML
Schumacher
W A
WA
D000818:Animals; D025901:Carboxypeptidase B2 / Q000097:blood; D002268:Carboxypeptidases / Q000037:antagonists & inhibitors; D002341:Carotid Artery Thrombosis / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy; D002712:Chlorides; D004195:Disease Models, Animal; D005290:Ferric Compounds / Q000633:toxicity; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010940:Plant Proteins / Q000008:administration & dosage / Q000494:pharmacology; D011480:Protease Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D011198:Solanum tuberosum; D015912:Thrombolytic Therapy; D014684:Venae Cavae; D020246:Venous Thrombosis / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy*
D002712:Chlorides; D005290:Ferric Compounds; D005343:Fibrinolytic Agents; D010940:Plant Proteins; D011480:Protease Inhibitors; D002268:Carboxypeptidases; D025901:Carboxypeptidase B2; C024555:ferric chloride