title: Formation of epoxyeicosatrienoic acids from arachidonic acid by cultured rat aortic smooth muscle cell microsomes.
abstract: The vasodilatory effect of epoxyeicosatrienoic acids (EpETrE), especially 5(6)-EpETrE, has been reported recently and a role of P-450-dependent arachidonic acid monooxygenase metabolites was suggested in vasoregulation. Accordingly, the presence of P-450-dependent arachidonic acid monooxygenase was investigated in rat aortic smooth muscle cells. Incubation of the microsomes of rat cultured aortic smooth muscle cells with 14C-arachidonic acid in the presence of 1 mM NADPH resulted in the formation of oxygenated metabolites. The metabolites were separated and purified by reverse phase and straight phase high performance liquid chromatography and identified by gas chromatography-mass spectrometry. Identified metabolites were 5(6)-EpETrE, 5,6-dihydroxyeicosatrienoic acid (DiHETrE), and 14,15-DiHETrE. The formation of these metabolites was totally dependent on the presence of NADPH, and inhibitors of cytochrome P-450-dependent enzymes, SKF-525A and metyrapone, reduced the formation of these metabolites. This is the first report that cytochrome P-450-dependent arachidonic acid metabolites, especially 5(6)-EpETrE and 14(15)-EpETrE, can be produced in the microsomes of vascular smooth muscle cells of rats.
authors.affiliation: Second Department of Internal Medicine, Chiba University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hasunuma
authors.forename: T
authors.initials: T
authors.lastname: Terano
authors.forename: Y
authors.initials: Y
authors.lastname: Tamura
authors.forename: S
authors.initials: S
authors.lastname: Yoshida
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D001426:Bacterial Proteins; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism; D007975:Leukotriene B4 / Q000378:metabolism / Q000031:analogs & derivatives; D008297:Male; D008797:Metyrapone / Q000494:pharmacology; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D009251:NADPH-Ferrihemoprotein Reductase; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D011921:Rats, Inbred WKY
chemical_list: D001095:Arachidonic Acids; D001426:Bacterial Proteins; D006893:Hydroxyeicosatetraenoic Acids; D011725:Pyridines; C013109:metapyrone; D007975:Leukotriene B4; D016718:Arachidonic Acid; D009249:NADP; C048698:5,6-dihydroxy-7,9,11,14-eicosatetraenoic acid; C030723:14,15-leukotriene B4; C040776:5,6-epoxy-8,11,14-eicosatrienoic acid; C046782:14,15-epoxy-5,8,11-eicosatrienoic acid; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D009251:NADPH-Ferrihemoprotein Reductase; C052423:flavocytochrome P450 BM3 monoxygenases; D015126:8,11,14-Eicosatrienoic Acid; D008797:Metyrapone