Changes of plasma fibrinolytic factors in pulmonary thromboembolism rats after rce-combinant prourokinase treatment / 军事医学

ABSTRACT

Objective To observe the changes in fibrinolytic factors in rats with pulmonary thromboembolism (PTE) after recombinant prourokinase ( rPro-UK) treatment and its significance .Methods PTE was induced in male Sprague-Dawley (SD) rats by injecting heated 125iodine-labeled fibrinogen(Fib) autologous thromboemboli into external jugular veins.Twenty-eight rats were randomly assigned into following groups (7 rats each)①healthy control group;②PTE 5 d group,the rats in which were sacrificed at 5 d after the PTE model was made; ③ PTE3d receiving rPro-UK thrombolytic treament groups including multibolus treatment sub group ( rPro-UK was given in 1 mg/kg on the post-PTE third day followed by 2 consecutive days of a lower dose 0.25 mg/kg and rats were sacrificed 2 h after the last injection at the same time as PTE5d group) and single bolus treatment sub group ( rPro-UK was given in 1 mg/kg on the post-PTE third day followed by 2 consecutive days of 0.5 ml saline and rats were sacrificad at the same time as the former group ).The rats were quickly sacrificad at the fixed time through carotid bleeding and plasma samples were reserved for analysis of uroki -nase-type plasminogen activator (u-PA), urokinase-type plasminogen activator receptor (u-PAR), fibrinogen (Fib) andα2-antiplasmin (α2-AP) .Results ①Plasma concentrations of u-PA and u-PAR were increased were significantly in rPro-UK multibolus treatment sub group than in PTE 5 d group(Pu-PA 0.05).Conclusion ① Plasma levels of endogenous u-PA and u-PAR are increased at different time points after PTE and are further enhanced after Pro-UK treatment, which promotes endogenous fibrinolysis and thrombus lysis .This is probably related to increased synthesis and secretion of endothelial cells which may be a key thrombolytic mechanism of Pro-UK.②Absence of systemic activation of the fibrinolytic system in Pro-UK multibo-lus treatment sub group means that the regimen is feasible and Pro-UK is fibrin specific .