Omega-hydroxylation of N-acetylleukotriene E4 by rat liver microsomes.

Previous investigations have demonstrated metabolism of leukotriene (LT) C4 in vivo involving transformations of the tripeptide, but not the fatty acid part, yielding N-acetyl LTE4 as a main biliary metabolite in the rat. In addition, several polar metabolites were detected in the same studies. The present report describes the characterization of a metabolite of N-acetyl LTE4 formed during incubations with rat liver microsomes. The structure, 5,20-dihydroxy-6-s-(2-acetamido-3-thiopropionyl)-7,9-trans-11, 14-cis-eicosa-tetraenoic acid, of this metabolite showed that it is formed by hydroxylation of the fatty acid part. Preliminary evidence indicates that it is one of several polar metabolites formed in vivo.