title: Kinetics of eicosapentaenoic acid in brain, heart and liver of conscious rats fed a high n-3 PUFA containing diet.
abstract: Eicosapentaenoic acid (EPA, 20:5n-3), a precursor of docosahexaenoic acid (DHA), may benefit cardiovascular and brain health. Quantifying EPA's in vivo kinetics might elucidate these effects. [1-(14)C]EPA was infused i.v. for 5min in unanesthetized male rats fed a standard EPA-DHA diet. Plasma and microwaved tissue were analyzed. Kinetic parameters were calculated using our compartmental model. At 5min, 31-48% of labeled EPA in brain and heart was oxidized, 7% in liver. EPA incorporation rates from brain and liver precursor EPA-CoA pools into lipids, mainly phospholipids, were 36 and 2529nmol/s/g×10(-4), insignificant for heart. Deacylation-reacylation half-lives were 22h and 38-128min. Conversion rates to DHA equaled 0.65 and 25.1nmol/s/g×10(-4), respectively. The low brain concentration and incorporation rate and high oxidation of EPA suggest that, if EPA has a beneficial effect in brain, it might result from its suppression of peripheral inflammation and hepatic conversion to bioactive DHA.
authors.affiliation: Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Building 9, Room 1S126, Bethesda, MD 20892, USA. Electronic address: miki.i@uci.edu.
authors.forename: Miki
authors.initials: M
authors.lastname: Igarashi
authors.forename: Lisa
authors.initials: L
authors.lastname: Chang
authors.forename: Kaizong
authors.initials: K
authors.lastname: Ma
authors.forename: Stanley I
authors.initials: SI
authors.lastname: Rapoport
mesh_terms: D000214:Acyl Coenzyme A / Q000032:analysis; D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D002250:Carbon Radioisotopes; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000378:metabolism; D015118:Eicosapentaenoic Acid / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D006207:Half-Life; D007700:Kinetics; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D000214:Acyl Coenzyme A; D002250:Carbon Radioisotopes; D015525:Fatty Acids, Omega-3; C056949:eicosapentaenoic acid-coenzyme A; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid
keywords: ALA; ARA; Brain; DHA; DPA; EPA; Eicosapentaenoic acid; FAME; GC; HPLC; Kinetics; LA; Metabolism; PC; PUFA; Rat docosahexaenoic; TLC; Turnover; arachidonic acid; docosahexaenoic acid (22:6n-3); docosapentaenoic acid (22:5n-3); eicosapentaenoic acid (20:5n-3); fatty acid methyl ester; gas chromatography; high performance liquid chromatography; linoleic acid (18:2n-6); phosphatidylcholine; polyunsaturated fatty acid; thin layer chromatography; α-linolenic acid (18:3n-3)