Effect of SANORG 34006 on rt-PA–induced thrombolysis in the rabbit. A ¹²⁵I-fibrinogen–labeled thrombus was formed in the jugular vein of rabbits. After thrombus formation, blood flow was restored and a 4-hour rt-PA infusion (0.5 mg/kg) was administered. SANORG 34006, SR 90107/ORG 31540, or heparin were administered at indicated doses as a bolus IV injection at the beginning of the rt-PA infusion. At the end of the infusion period, the amount of radioactivity remaining in the clot was determined with a gamma counter (A) and the thrombus was weighed (B). The extent of¹²⁵I-fibrino(geno)lysis was calculated as the difference between the radioactivity originally incorporated in the thrombus and the remaining radioactivity in the residual thrombus. Values are means ± SEM (n = 8). Statistical analysis was performed using the Mann-Whitney test: *P < .05 versus rt-PA–treated group.