title: Heparin requirement in tissue-type plasminogen activator-induced experimental coronary thrombolysis: comparison with urokinase-induced coronary thrombolysis.
abstract: The requirement of heparin in experimental coronary thrombolysis induced by tissue-type plasminogen activator (t-PA) was studied in closed-chest dogs with one hour old coronary thrombi and compared with that in urokinase (UK)-induced coronary thrombolysis. Animals were divided into 5 treatment groups as follows: group 1 received intracoronary t-PA alone (1,000 IU/kg/min; n = 5), and if thrombolysis was not induced within 40 to 50 min, dogs then received an intravenous injection of heparin (300 U/kg) plus intracoronary t-PA; group 2 received intravenous heparin at first, and if thrombolysis was not induced within 10 min, dogs subsequently received intracoronary t-PA (n = 5); group 3 also received intravenous heparin at first, and if thrombolysis was not induced within 10 min, dogs subsequently received t-PA but intravenously, as compared with the groups administered by the intracoronary route (n = 6); group 4 received intracoronary UK alone (1,000 IU/kg/min; n = 6); group 5 received intravenous heparin at first, and if thrombolysis was not induced within 10 min, dogs subsequently received intracoronary UK (n = 5). Thrombolysis was confirmed angiographically. In group I, coronary thrombolysis could not be induced within 44 +/- 4 min by intracoronary t-PA alone, but it occurred in 8 +/- 4 min when administered in combination with heparin in all dogs. Heparin alone failed to elicit reperfusion within 10 min in group 2, 3 and 5. t-PA, however, induced successful reperfusion in 16 +/- 5 min (group 2) and in 23 +/- 6 min (group 3), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000818:Animals; D003327:Coronary Disease / Q000188:drug therapy*; D003328:Coronary Thrombosis / Q000097:blood / Q000188:drug therapy*; D003331:Coronary Vessels; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D004359:Drug Therapy, Combination; D005340:Fibrinogen / Q000032:analysis; D006493:Heparin / Q000627:therapeutic use*; D007261:Infusions, Intra-Arterial; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D014568:Urokinase-Type Plasminogen Activator / Q000627:therapeutic use*; D000979:alpha-2-Antiplasmin / Q000032:analysis
chemical_list: D000979:alpha-2-Antiplasmin; D005340:Fibrinogen; D006493:Heparin; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator