The Transport of ‘251-Labeled Human High Molecular Weight Urokinase Across the Intestinal Tract in a Dog Model With Stimulation of Synthesis and/or Release of Plasminogen Activators

In an attempt to elucidate the mechanism of fibrinolytic enhancement by orally administered urokinase, studies on the intestinal transport of urokinase were carried out, using 1251-labeled human high mol wt urokinase, administered intraduodenally in the experimental dog model with a saphenous vein thrombus. Using the plasma sample obtained from blood 45 minutes after intraduodenal administration of the urokinase, protein fractions were isolated by a sequential two-step affinity chromatography method. first with [N”-(#{128}-aminocaproyl)-DL-homoarginine hexylesterj-Sepharose followed by a specific anti-human low mol wt urokinase rabbit lgG-Sepharose (adsorbed-eluted and unadsorbed). Each of the isolated protein fractions was further purified by gel filtration on Sephacryl S-300. The proteins isolated by the two-step affinity chromatography method were transported human urokinase with radioactivity in the adsorbed-eluted fraction, and newly synthe-