title: Conjugated linoleic acid, cis-9,trans-11, is a substrate for pulmonary 15-lipoxygenase-1 in rat.
abstract: The objective of this study was to determine whether two of the major conjugated linoleic acid (CLA) isomers, cis-9,trans-11 (c9,t11) and trans-10,cis-12 (t10,c12), are possible substrates for pulmonary 15-lipoxygenase-1 (15-LOX-1) and, therefore, they are also involved in the production of 13(S)-hydroxyoctadecadienoic acid [13(S)-HODE] in biological systems. 13(S)-HODE, a major bioactive metabolite of linoleic acid, is an important intracellular signal agent and is involved in cell proliferation and differentiation in various biological systems. Nordihydroguaiaretic acid (NDGA), a known LOX inhibitor, was used as a control for measuring 15-LOX-1 enzyme activity. It was found that c9,t11-CLA was 25% as active as linoleic acid as a substrate for 15-LOX-1; however, t10,c12-CLA was not a substrate for 15-LOX-1 as measured by 13(S)-HODE production. The authenticity of the production of 13(S)-HODE from c9,t11 as a substrate was established by isolation and cochromatography with pure standard on HPLC using non-radioactive and [14C]-c9,t11-CLA.
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Avenue, St. Paul, Minnesota 55108, USA.
authors.forename: Hyejung
authors.initials: H
authors.lastname: Cho
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Gallaher
authors.forename: A Saari
authors.initials: AS
authors.lastname: Csallany
mesh_terms: D000818:Animals; D001093:Arachidonate 15-Lipoxygenase / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008041:Linoleic Acids / Q000378:metabolism; D044243:Linoleic Acids, Conjugated / Q000378:metabolism*; D016859:Lipoxygenase Inhibitors; D008168:Lung / Q000201:enzymology*; D008297:Male; D009637:Masoprocol / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D004791:Enzyme Inhibitors; D008041:Linoleic Acids; D044243:Linoleic Acids, Conjugated; D016859:Lipoxygenase Inhibitors; C024348:13-hydroxy-9,11-octadecadienoic acid; D009637:Masoprocol; D001093:Arachidonate 15-Lipoxygenase