title: Antithrombotic effect of TRK-100, a novel, stable PGI2 analogue.
abstract: TRK-100, a stable PGI2 analogue structurally different from carbacyclines, was compared with other antiplatelet drugs for its effect on platelet functions using animal models. TRK-100 (10-300 nM) inhibited rat platelet aggregation induced by ADP (3 microM), collagen (12.5 micrograms/ml) and A23187 (10 microM), and its potency was about 1/3-1/7 that of PGI2. TRK-100 (0.3-3 mg/kg, p.o.) dose-dependently inhibited rabbit platelet adhesion (ED50: 2.2 mg/kg), and its effect lasted over at least 5 hr. In contrast, aspirin and ticlopidine (both at 300 mg/kg, p.o.) showed only a slight inhibition (4-7%). In the thrombocytopenia induced by collagen injection in rats, TRK-100 (3-300 micrograms/kg, i.v.; 0.1-3 mg/kg, p.o.) dose-dependently inhibited a decrease in platelet number, and its ED50 was 0.48-0.62 mg/kg orally and 13.7-16.4 micrograms/kg intravenously, while the inhibition by aspirin and ticlopidine (both at 1000 mg/kg, p.o.) was 40 and 37%, respectively. In the experimental thread thrombosis in rats. TRK-100 (0.03-3 mg/kg, p.o.) dose-dependently inhibited thrombus formation, and its ED50 was 0.46 mg/kg, being 21 and 87 times as potent as aspirin and ticlopidine, respectively. These results reveal that TRK-100 has a potent antiplatelet activity and is orally and intravenously effective for a variety of thrombosis models, suggesting that it may have a therapeutic value as an antithrombotic drug.
mesh_terms: D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D003094:Collagen / Q000037:antagonists & inhibitors; D011464:Epoprostenol / Q000494:pharmacology* / Q000031:analogs & derivatives; D005343:Fibrinolytic Agents; D066298:In Vitro Techniques; D008297:Male; D010973:Platelet Adhesiveness / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013988:Ticlopidine / Q000494:pharmacology
chemical_list: D005343:Fibrinolytic Agents; C048081:beraprost; D003094:Collagen; D011464:Epoprostenol; D013988:Ticlopidine; D001241:Aspirin