Transformation of arachidonic acid and homo-gamma-linolenic acid by rabbit polymorphonuclear leukocytes. Monohydroxy acids from novel lipoxygenases

Abstract

Addition of arachidonic acid and homo-gamma-linolenic acid to a suspension of rabbit peritoneal neutrophils led to the synthesis of 5-L-hydroxy-6,8,11,14-eicosatetraenoic acid and 8-L-hydroxy-9,11,14-eicosatrienoic acid, respectively. Both hydroxy acids were found to be the main metabolites of their respective unsaturated C-20 fatty acid precursor, constituting more than 50% of the total substrate conversion. The formation of the two metabolites was not inhibted bb indomethacin, indicating that the enzymes involved were unrelated to the prostaglandin synthetase system. The presence in the two compounds of a hydroxyl group alpha to a pair of conjugated cis/trans double bonds suggested that they were formed by action of lipoxygenease(s).