title: Thrombus age and tissue plasminogen activator mediated thrombolysis in rats.
abstract: Thrombolytic efficacy is directly related to thrombus age. We used recombinant tissue plasminogen activator (rt-PA), Streptokinase (SK) and Urokinase (UK) on a seven days old inferior vena cava thrombus model. "In vitro" clot lysis assays with fibrinogen-I125 were also evaluated with the same agents at 1, 3 and 7 days. Fibrinogen, D-D dimer and t-PA were measured. Experiments with 40 controls and 27 rt-PA treated animals showed a significant decrease in thrombus weight (8.5 +/- 1.1 mg) vs. (4.2 +/- 0.6 mg) (p less than 0.01). Fibrinogen concentration in rt-PA group decreased significantly (1032 +/- 123 mg/dl) vs. (202 +/- 32 mg/dl) (p less than 0.001). "In vitro" rt-PA showed a marked lytic effect in a wide range (100-4 IU/ml). Fibrin selective agents as rt-PA may be more effective than non selective ones in the treatment of fully developed thrombus.
authors.affiliation: Haematology Department, Ramón y Cajal Hospital, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Loren
authors.forename: L J
authors.initials: LJ
authors.lastname: García Frade
authors.forename: M C
authors.initials: MC
authors.lastname: Torrado
authors.forename: J L
authors.initials: JL
authors.lastname: Navarro
mesh_terms: D000818:Animals; D005340:Fibrinogen / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D015912:Thrombolytic Therapy; D013927:Thrombosis / Q000188:drug therapy*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*
chemical_list: D005340:Fibrinogen; D010959:Tissue Plasminogen Activator