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 EM. 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. Platelets in various stages of activation were identified. Apparently the commonly employed thrombolytic agents, urokinase and streptokinase, caused injury to the endothelial cells of the animal model. Evidently 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.