Pt. Onundarson et al., PLASMINOGEN DEPLETION DURING STREPTOKINASE TREATMENT OR 2-CHAIN UROKINASE INCUBATION CORRELATES WITH DECREASED CLOT LYSABILITY EX-VIVO AND IN-VITRO, Thrombosis and haemostasis, 70(6), 1993, pp. 998-1004
The relationship between lytic state variables and ex vivo clot lysabi
lity was investigated in blood drawn from patients during streptokinas
e administration for acute myocardial infarction. A lytic state was al
ready evident after 5 min of treatment and after 20 min the plasminoge
n concentration had decreased to 24%, antiplasmin to 7% and fibrinogen
0.2 g/l. Lysis of radiolabeled retracted clots in the patient plasmas
decreased from 37 +/- 8% after 5 min to 21 +/- 8% at 10 min and was s
ignificantly lower (8 +/- 9%, p <0.005) in samples drawn at 20, 40 and
80 min. Clot lysability correlated positively with the plasminogen co
ncentration (r = 0.78, p = 0.003), but not with plasmin activity. Susp
ension of radiolabeled clots in normal plasma pre-exposed to 250 U/ml
two-chain urokinase for varying time to induce an in vitro lytic state
was also associated with decreasing clot lysability in direct proport
ion with the duration of prior plasma exposure to urokinase. The decre
ased lysability correlated with the time-dependent reduction in plasmi
nogen concentration (r = 0.88, p <0.0005). Thus, clot lysability decre
ases in conjunction with the development of the lytic state and the as
sociated plasminogen depletion. The lytic state may therefore limit re
perfusion during thrombolytic treatment.