Studies on antiplatelet effect of OP-41483, a prostaglandin I2 analog, in experimental animals. I. Effect on platelet function and thrombosis.
Antiplatelet and antithrombotic effects of OP-41483, a PGl2 analog, were studied in experimental animals, and the following results were obtained: 1) With 10 min-intravenous infusion to guinea pigs, OP-41483 inhibited platelet adhesiveness and platelet aggregation at 300-1000 ng/kg/min and 1000 ng/kg/min, respectively. In these effects, OP-41483 was 1-3 times more potent than carbacyclin and 3 times less potent than PGl2. 2) With oral administration to guinea pigs, OP-41483 given as its alpha-cyclodextrin clathrate (OP-41483 alpha-CD) inhibited platelet adhesiveness at doses higher than 1.0 mg/kg (expressed in terms of OP-41483), whereas PGl2 and carbacyclin did not at 10 mg/kg. OP-41483 alpha-CD also inhibited platelet aggregation after a single dose of 3 mg/kg and repeated doses of 3 mg/kg/day for 7 days. 3) In the electrically induced thrombosis model of guinea pig mesenteric artery, OP-41483 (300-1000 ng/kg/min, i.v.-infusion) and OP-41483 alpha-CD (1.0-3.0 mg/kg, p.o.) inhibited thrombus formation, but heparin (1.0-10 U/kg/min, i.v.-infusion) did not. 4) In the rabbit extracorporeal circulation thrombosis model, OP-41483 (100 and 300 ng/kg/min, i.v.-infusion) inhibited thrombus formation in the extracorporeal shunt and prevented the decrease in platelet count, hematocrit and fibrinogen level in circulating blood. Heparin (1.0-3.0 U/kg/min, i.v.-infusion) also inhibited the thrombus formation and the decrease in fibrinogen level, but did not inhibit the decrease in hematocrit and platelet count.
Fujitani
B
B
Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Osaka, Japan.
Wakitani
K
K
D000818:Animals; D004558:Electric Stimulation; D004564:Electrocoagulation; D011464:Epoprostenol / Q000494:pharmacology* / Q000031:analogs & derivatives; D005112:Extracorporeal Circulation; D006168:Guinea Pigs; D006400:Hematocrit; D006493:Heparin / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D010979:Platelet Function Tests; D011817:Rabbits; D013927:Thrombosis / Q000517:prevention & control*
D010975:Platelet Aggregation Inhibitors; C026678:carboprostacyclin; D006493:Heparin; D011464:Epoprostenol; C035847:ataprost