title: Evidence for lipoxin formation by bovine polymorphonuclear leukocytes via triple dioxygenation of arachidonic acid.
abstract: Incubation of bovine polymorphonuclear leukocytes (PMNs) with arachidonic acid leads to the formation of four lipoxins. The same lipoxins are also formed upon incubation of bovine PMNs with 5(S)-hydroperoxy-6-trans-8,11,14-cis-eicosatetraenoic acid, 5-hydroxy-6-trans-8,11,14-cis-eicosatetraenoic acid, 5(S)-hydroperoxy, 15(S)-hydroxy-6,13-trans-8,11-cis-eicosatetraenoic acid or 5(S),15(S)-dihydroxy-6,13-trans-8,11-cis-eicosatetraenoic acid. A 5,6-epoxide as intermediate in lipoxin formation in the bovine PMN is highly improbable because the 5-hydroxy compounds are as good substrates as the 5-hydroperoxy compounds. Moreover, the two main lipoxins were found to coelute with the two lipoxins produced via a triple dioxygenation of arachidonic acid by soybean lipoxygenase-1. Hence the bovine PMN is the first cell for which evidence is presented that the formation of lipoxins proceeds mainly via triple dioxygenation and not via 15-hydroxy-leukotriene A4 as is proposed for human and porcine PMNs.
mesh_terms: D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood*; D002417:Cattle; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000096:biosynthesis*; D044045:Lipoxins; D009504:Neutrophils / Q000378:metabolism*; D010084:Oxidation-Reduction; D013552:Swine
chemical_list: D001095:Arachidonic Acids; D006893:Hydroxyeicosatetraenoic Acids; D044045:Lipoxins; C040527:lipoxin A4; D016718:Arachidonic Acid; C042651:lipoxin B4