SC-57461A

Leukotriene A4 (LTA4) hydrolase/aminopeptidase is a bifunctional zinc metalloenzyme that both catalyzes the synthesis of LTB4 (Item No. 20110) from LTA4 and cleaves the chemotactic peptide Pro-Gly-Pro.{12673,20329} SC-57461A is a potent, orally active inhibitor of LTA4 hydrolase that blocks ionophore-stimulated LTB4 synthesis in whole blood (IC50 = 49 nM).{31025,31023} It blocks both the hydrolase and aminopeptidase activity in vitro.{31023} SC-57461A is without effect against other enzymes of the arachidonic acid cascade, including 5-lipoxygenase, LTC4 synthase, COX-1, and COX-2. In a rat model of ionophore-induced peritoneal eicosanoid production, SC-57461A inhibits LTB4 biosynthesis without affecting LTC4 (Item No. 20210) or 6-keto prostaglandin F1? production (Item No. 15210).{31024} Oral or topical pretreatment with SC-57461A before challenge with arachidonic acid blocks ear edema in mice.{31024}