title: Effect of Piriprost, a 5-lipoxygenase inhibitor, on leukocyte accumulation during thioglycollate-induced acute inflammation.
abstract: We evaluated the effect of a prototype 5-lipoxygenase enzyme inhibitor, Piriprost [6,9-deepoxy-6,9-(phenylimino-)delta 6,8-prostaglandin I1], on the leukocyte accumulation induced by intraperitoneal injection of thioglycollate in rats. Piriprost, at 40 mg/kg, i.p., inhibited leukocyte accumulation by 34 +/- 12% (mean +/- S.D., n = 9). With experimental groups containing small numbers of rats (6 to 9) inhibition was statistically significant in 7 of 9 cases. Piriprost shared this property with dexamethasone; however, dexamethasone at 5 mg/kg, p.o., inhibited leukocyte accumulation to a greater extent, 61 +/- 6% (mean +/- S.D., n = 5) and the inhibition was statistically significant in 5 of 5 cases. Conventional non-steroidal antiinflammatory agents including aspirin and phenylbutazone were ineffective in our model. Our results suggest that certain compounds that inhibit the 5-lipoxygenase enzyme, without inhibiting the cyclooxygenase enzyme, can reduce the leukocyte accumulation associated with acute inflammation.
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D001091:Arachidonate Lipoxygenases; D003907:Dexamethasone / Q000494:pharmacology; D011464:Epoprostenol / Q000494:pharmacology* / Q000031:analogs & derivatives; D005260:Female; D007962:Leukocytes / Q000187:drug effects* / Q000276:immunology; D016859:Lipoxygenase Inhibitors; D010538:Peritonitis / Q000139:chemically induced / Q000276:immunology*; D051381:Rats; D011919:Rats, Inbred Strains; D013189:SRS-A / Q000037:antagonists & inhibitors*; D013864:Thioglycolates
chemical_list: D000893:Anti-Inflammatory Agents; D016859:Lipoxygenase Inhibitors; D013189:SRS-A; D013864:Thioglycolates; D003907:Dexamethasone; D011464:Epoprostenol; D001091:Arachidonate Lipoxygenases; C035296:piriprost