title: Oxatomide inhibits the release of bronchoconstrictor arachidonic acid metabolites (iLTC4 and PGD2) from rat mast cells and guinea-pig lung.
abstract: The effect of oxatomide, an orally active antiallergic drug, on immunoreactive LTC4 (iLTC4) production has been studied in rat peritoneal exudate cells (PEC) and guinea-pig lung fragments using the calcium ionophore A23187 and specific antigen in vitro. Oxatomide (10(-5) M) inhibited iLTC4 release by 70% with A23187 from rat PEC, and by 48% with antigen from guinea-pig lung. Oxatomide is supposed to affect the biosynthesis pathway of leukotrienes, because oxatomide inhibits 5-lipoxygenase from guinea-pig peritoneal leukocytes with an IC50 17 microM. Oxatomide also depressed the release of PGD2 from rat peritoneal mast cells stimulated by A23187 (IC50 4.2 microM). The effects of oxatomide on iLTC4 and PGD2 release were more potent than other antiallergic drugs (DSCG, ketotifen, tranilast).
mesh_terms: D000818:Animals; D001094:Arachidonate 5-Lipoxygenase / Q000032:analysis; D000001:Calcimycin / Q000494:pharmacology; D004205:Cromolyn Sodium / Q000494:pharmacology; D006168:Guinea Pigs; D007665:Ketotifen / Q000494:pharmacology; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism*; D010879:Piperazines / Q000494:pharmacology*; D015230:Prostaglandin D2; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis; D011457:Prostaglandins D / Q000378:metabolism*; D051381:Rats; D013189:SRS-A / Q000378:metabolism*; D062367:ortho-Aminobenzoates / Q000494:pharmacology
chemical_list: D010879:Piperazines; D011457:Prostaglandins D; D013189:SRS-A; D062367:ortho-Aminobenzoates; D000001:Calcimycin; D001094:Arachidonate 5-Lipoxygenase; D011451:Prostaglandin-Endoperoxide Synthases; C012293:tranilast; C015408:oxatomide; D004205:Cromolyn Sodium; D015230:Prostaglandin D2; D007665:Ketotifen