Thrombolytic agents: effects of local infusion on microvascular physiology and macrovascular ultrastructure.

Abstract

Microvascular responses in live preparations of rat cremaster muscle were studied with intravital light microscopy following infusions of streptokinase, streptokinase-plasminogen complex, or urokinase into the iliac artery. Structural changes occurring in the endothelium of the iliac arteries were documented by electron microscopy. Though no functional microvascular changes were documented, endothelial cell injury and luminal surface fibrin deposits were identified in the iliac arteries locally infused with the thrombolytic agents. In addition, platelets in various stages of activation were identified. It is concluded that the commonly employed thrombolytic agents, urokinase and streptokinase, caused injury to the endothelial cells of our animal model. It is further concluded that platelet activation, due to local endothelial injury or some other mechanism, occurred following local infusion in our animal model. The long-term effects and potential clinical implications of the findings are not known.

The Systemic Fibrinolytic Effect of BRL 26921 During the Treatment of Acute Peripheral Arterial Occlusions

“…Added susceptibility to thrombosis may exist for 24 h after thrombolytic therapy due to reduced availability of plasminogen (3) but only one of the eight thromboses in the present study occurred then. Streptokinase may activate platelets increasing the risk of thrombosis in the period after treatment (22). Therefore patients in this study who were unable to take warfarin were given antiplatelet therapy for three months.…”