669
Fig 2-Representative G-banded karyotype of tumour cells.
combination with heparin seemed to explain the bleeding. However, in contrast to the other trials, all patients in the angina pectoris group were simultaneously treated with a standard drug regimen, consisting mainly of nitrovasodilators. We speculated that the bleeding observed resulted from the prolongation of the fibrinolytic activity of t-PA by nitrovasodilators. To test this hypothesis we have done some experiments in New Zealand white rabbits anaesthetised with sodium pentobarbitone (20 mg/kg intravenously). Fibrinolytic activity was estimated by measuring t-PA activity (’Spectrolyse’ kit; Biopool, Sweden) in plasma before and 1, 5, 15, 30, and 60 min after the intravenous administration of single-chain t-PA (30 )Jg/kg; Biopool) and/or sodium nitroprusside (30 pg/kg; Sigma). Injection of t-PA increased t-PA activity in the sample drawn after 1 min, but activity had returned to baseline within 5 min (figure). Sodium nitroprusside alone had little effect on t-PA activity (from 0 48 but co[SEM 0-05] to 0-73 [0’09] IU/ml, n=4; p
Fig 2-Representative G-banded karyotype of tumour cells.
combination with heparin seemed to explain the bleeding. However, in contrast to the other trials, all patients in the angina pectoris group were simultaneously treated with a standard drug regimen, consisting mainly of nitrovasodilators. We speculated that the bleeding observed resulted from the prolongation of the fibrinolytic activity of t-PA by nitrovasodilators. To test this hypothesis we have done some experiments in New Zealand white rabbits anaesthetised with sodium pentobarbitone (20 mg/kg intravenously). Fibrinolytic activity was estimated by measuring t-PA activity (’Spectrolyse’ kit; Biopool, Sweden) in plasma before and 1, 5, 15, 30, and 60 min after the intravenous administration of single-chain t-PA (30 )Jg/kg; Biopool) and/or sodium nitroprusside (30 pg/kg; Sigma). Injection of t-PA increased t-PA activity in the sample drawn after 1 min, but activity had returned to baseline within 5 min (figure). Sodium nitroprusside alone had little effect on t-PA activity (from 0 48 but co[SEM 0-05] to 0-73 [0’09] IU/ml, n=4; p
