[Low molecular weight heparin CY 222 (Choay) potentiates the thrombolytic effect of 1-PA in rabbits with experimental thrombosis of the jugular vein].

The effect of a low molecular weight heparin CY 222 (Choay) on t-PA induced thrombolysis was investigated in the rabbit jugular thrombosis model. The compound CY 222 was administered as 1.4 mg/kg (group A) by IV injection immediately after start of t-PA infusion (0.125 and 0.250 mg/kg) and then hourly during the 4 hours of infusion of the thrombolytic; results were compared with those obtained in the absence of CY 222 (group B). A significant increase in percent thrombolysis was noted in the presence of CY 222: A versus B = 31 +/- 1/22 +/- 2 (p less than 0.02) (tPA = 0.125 mg/kg; 72 +/- 4/36 +/- 3 (p less than 0.01) (tPA = 0.250 mg/kg). Anti-Xa activity 60 minutes after 1.2 u/ml IV of CY 222 was comparable with that observed in patients with venous thrombosis treated with high-dose CY 222. The conclusion is reached of the interest of CY 222 in combination with t-PA, the CY 222 acting not only on coagulation by also on thrombolysis by potentiating the effect of t-PA.