title: Epoxide hydratase assay in human platelets using hepoxilin A3 as a lipid substrate.
abstract: 1-14C-labelled hepoxilin A3 (8-hydroxy-11,12-epoxyeicosa-5,9,14-trienoic acid) was generated from 1-14C-labelled arachidonic acid during incubation with a rat lung preparation lacking epoxide hydratase activity. The HPLC purified hepoxilin A3 gave only two isomeric 8,11,12-triols (termed trioxilins A3) upon incubation with a rat lung preparation containing epoxide hydratase activity. Based on this simple reaction an assay was developed using only 2000 cpm/tube of substrate and aliquots of a homogenate of platelet membranes from man. Products were assayed by thin-layer radiochromatography. Males were noted to have higher epoxide hydratase activity for this substrate than females.
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*; D000818:Animals; D001792:Blood Platelets / Q000201:enzymology*; D055598:Chemical Phenomena; D002621:Chemistry; D002855:Chromatography, Thin Layer; D004851:Epoxide Hydrolases / Q000097:blood*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008168:Lung / Q000378:metabolism; D051381:Rats
chemical_list: D005231:Fatty Acids, Unsaturated; C038243:8-hydroxy-11,12-epoxyeicosa-5,9,14-trienoic acid; D004851:Epoxide Hydrolases; D015126:8,11,14-Eicosatrienoic Acid