[Effect of (+)-S-145 calcium salt dihydrate, an orally active antagonist of the thromboxane A2/prostaglandin endoperoxide receptor, on platelet aggregation].
The effect of (+)-S-145, (1R, 2S, 3S, 4S)-(5Z)-7-(3-phenylsulfonylaminobicyclo [2.2.1] hept-2-yl) heptenoic acid on human and guinea pig platelet aggregation was examined. (+)-S-145 sodium salt inhibited human platelet aggregation induced by arachidonic acid (AA), 9,11-methanoepoxy-PGH2 (U 46619), collagen, ADP or epinephrine with the IC50 being 0.047-0.146 microM in an in vitro system. When (+)-S-145 calcium salt dihydrate was administered orally to guinea pigs, it inhibited AA-, U-46619- or collagen-induced platelet aggregation dose-dependently with the minimum effective dose being 0.03 mg/kg, and the effective duration being maximally 3 hr. The inhibiting potency and effective duration of (+)-S-145 calcium salt dihydrate after multiple administrations, once a day (0.5 mg/kg) for 7 days, were almost the same as those after a single administration. Although (+)-S-145 sodium salt showed a partial agonist effect (shape change) on platelets in vitro, the effect diminished after pretreatment of the platelets with a lower dose of this compound. These data suggest that (+)-S-145 calcium salt dihydrate is an orally effective potent platelet aggregation inhibitor.
Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan.
H
H
Kakushi
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T
Shike
Y
Y
Hayasaki
H
H
Arita
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K
Uchida
D000244:Adenosine Diphosphate / Q000037:antagonists & inhibitors; D000284:Administration, Oral; D000818:Animals; D016718:Arachidonic Acid / Q000037:antagonists & inhibitors; D001643:Bridged Bicyclo Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D003094:Collagen / Q000037:antagonists & inhibitors; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000037:antagonists & inhibitors; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage / Q000494:pharmacology*; D006168:Guinea Pigs; D006801:Humans; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011450:Prostaglandin Endoperoxides, Synthetic / Q000037:antagonists & inhibitors; D011982:Receptors, Prostaglandin / Q000037:antagonists & inhibitors*
D001643:Bridged Bicyclo Compounds; D005229:Fatty Acids, Monounsaturated; D010975:Platelet Aggregation Inhibitors; D011450:Prostaglandin Endoperoxides, Synthetic; D011982:Receptors, Prostaglandin; C056566:S 145; D016718:Arachidonic Acid; D000244:Adenosine Diphosphate; D003094:Collagen; D004837:Epinephrine