RESUMO
<p><b>OBJECTIVE</b>This study investigated the thrombolitic effect of Tianma Xinnao capsule and its preliminary mechanism, as well as the effect on coagulation system.</p><p><b>METHOD</b>Charlton's and Tomihisa's methods were modified to investigate the thrombolytic effect of Tianma Xinnao capsule. The activities of type 1 plasminogen activator inhibitor (PAI-1) and tissue-type plasminogen activator (tPA) in rabbit plasma were assayed by use of ELISA. The effects of Tianma Xinnao capsule were also evaluated on euglobulin lysis time (ELT), prothrombin time (PT), kaolin partial thromboplastin time (KPTT), thrombin time (TT), fibrinogen (Fib) and hemorheology.</p><p><b>RESULT</b>The results showed that Tianma Xinnao capsule had a dose-dependent thrombolytic effect in rats. Tianma Xinnao capsule at 0.6 and 1.2 g x kg(-1) produced 40% and 50% of reperfusion rate, while obtained 50% and 40% of reocclusion rate; 0.3 g x kg(-1) of Tianma Xinnao capsule, however, had no effect on the reperfusion or reocclusion rate. Tianma Xinnao capsule significantly inhibited PAI-1 activity, while elevated tPA activity in rabbit plasma. Tianma Xinnao capsule markedly prolonged ELT, PT, and KPTT, and decreased Fib level. Tianma Xinnao capsule showed no significant influence on TT or high, medium, or low sheering viscosity.</p><p><b>CONCLUSION</b>It is indicated that Tianma Xinnao capsule inhibited PAI-1 activity and increased tPA activity, and this property of Tianma Xinnao capsule is assigned to be responsible for the thrombolytic effect.</p>