Metabolism of lipoxins A4 and B4 and of their all-trans isomers by human leukocytes and rat liver microsomes.
Incubation of lipoxin A4 (LXA4) either with human leukocytes or with rat liver microsomes in the presence of NADPH very selectively led to a more polar metabolite retaining the conjugated tetraenic structure of LXA4. Lipoxin B4 (LXB4) underwent a very similar metabolism into a more polar metabolite, whereas the all-trans isomers of LXA4 and LXB4 were selectively transformed by the same biological systems into metabolites derived from the reduction of one of the double bonds of the conjugated tetraene moiety of the starting compounds. Microsomal metabolism of LXA4 and LXB4 was NADPH-dependent and strongly inhibited by CO and miconazole indicating the involvement of cytochrome P-450 monooxygenase enzymes. Striking similarities between the metabolism of lipoxins and that of leukotriene B4 (LTB4) suggest that LXA4 and LXB4 are mainly hydroxylated, on omega or omega-I position, by human leukocytes and rat and human liver microsomes, whereas their all-trans isomers are mainly reduced into conjugated trienic compounds.
Boucher
J L
JL
Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UA 400 CNRS, Université René Descartes, Paris, France.
Delaforge
M
M
Mansuy
D
D
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism*; D066298:In Vitro Techniques; D007536:Isomerism; D007700:Kinetics; D044045:Lipoxins; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D009504:Neutrophils / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D006893:Hydroxyeicosatetraenoic Acids; D044045:Lipoxins; C040527:lipoxin A4; C042651:lipoxin B4