Local plasminogen activator and prostacyclin-like activity after partial venous occlusion--an experimental study in...

After 90 min. of partial venous occlusion (40%) in dog's femoral vein plasminogen activator (t-PA) was decreased in the pre-occlusion segment and maintained in the post-occlusion segment. Prostacyclin-like activity (PLA) was maintained in the pre-, but increased in the post-occlusion segment. Treatment with heparin (loading dose-70/kg; IV perfusion-1 U/kg/min) did not affect pre-treatment pattern of t-PA or PLA in either segments. Treatment with aspirin (IV perfusion-2 mg/kg/min) promoted profound depression of PLA in both segments while t-PA remained unchanged. Treatment with lidocain (loading dose-1.5 mg/kg; IV perfusion 0.2 mg/kg/min) did not affect either PLA or t-PA in the pre-occlusion segment, but a decrease of these two activities was observed in the post-occlusion segment. We conclude that, since thrombin, prostaglandins and white blood cells were not responsible for all changes observed at t-PA and PLA vessel wall levels, it is justified, to evaluate the role of rheological factors as the probable determinant of these changes.