Effect of diftalone and other nonsteroidal anti-inflammatory agents on synthesis of prostaglandins (38560).
Diftalone and its metabolites 7, 14-Dihydroxyphthalzino  (2,3-b)phthalazine-5, 12 (7H,  14H)-dione, 7-Hydroxyphthalazino (2, 3-b)phthalzine-5,12 (7H, 14H)=DIONE, AND 12 (1(2H)-oxo-2-phthalazinyl)methylbenzoic acid inhibited prostaglandin synthesis in bovine seminal vesicle microsome preparations.  Diftalone was the most active of these compounds but less active than indomethacin although more active than phenylbutazone or asprin.  The magnitude of the concentration of arachidonic acid influenced the velocity of the reaction in the synthesis of prostaglandins; the highest concentrations inhibited the rate of reaction.  The results of the in vitro inhibition of prostaglandin synthetase studies correlated well with those obtained in the in vivo carrageenan edema inhibition studies in the rat.  The relative potencies for Diftalone, indomethacin and phenylbutazone were similar with both experimental procedures.
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001095:Arachidonic Acids / Q000378:metabolism; D001241:Aspirin / Q000494:pharmacology; D001667:Binding, Competitive; D002417:Cattle; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008861:Microsomes / Q000378:metabolism; D010653:Phenylbutazone / Q000494:pharmacology; D010793:Phthalazines / Q000494:pharmacology*; D011453:Prostaglandins / Q000096:biosynthesis*; D011724:Pyridazines / Q000494:pharmacology*; D012669:Seminal Vesicles / Q000378:metabolism* / Q000648:ultrastructure
D000893:Anti-Inflammatory Agents; D001095:Arachidonic Acids; D010793:Phthalazines; D011453:Prostaglandins; D011724:Pyridazines; D010653:Phenylbutazone; D001241:Aspirin; D007213:Indomethacin