title: Dietary docosahexaenoic acid is retroconverted in man to eicosapentaenoic acid, which can be quickly transformed to prostaglandin I3.
abstract: In a 24 h kinetic study docosahexaenoic acid (DCHA, C22:6n-3) or eicosapentaenoic acid (EPA, C20:5n-3) were given in a single dose to healthy male volunteers. PGI3-M, the main urinary metabolite of prostaglandin I3 was below the detection limit in the control periods, but was excreted already in the first 4 h after ingestion of DCHA or EPA and decreased thereafter. Excretion of PGI2-M did not change significantly. In a second dietary trial DCHA and EPA were given cross-over to 7 healthy male volunteers for 6 days. PGI3-M was formed after DCHA and EPA in amounts of 35 and 20% of PGI2-M and showed a considerable interindividual variation. The structure of PGI3-M was verified by independent biochemical synthesis. Our data indicate that dietary DCHA is retroconverted to EPA in man, which is quickly transformed--like dietary EPA itself--to prostaglandin I3. DCHA may therefore serve as a precursor fatty acid for EPA and its cyclooxygenated and lipoxygenated products.
authors.affiliation: Medizinische Universitätsklinik Innenstadt, München, F.R.G.
authors.forename: S
authors.initials: S
authors.lastname: Fischer
authors.forename: A
authors.initials: A
authors.lastname: Vischer
authors.forename: V
authors.initials: V
authors.lastname: Preac-Mursic
authors.forename: P C
authors.initials: PC
authors.lastname: Weber
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism; D002417:Cattle; D004041:Dietary Fats / Q000378:metabolism*; D004281:Docosahexaenoic Acids / Q000378:metabolism* / Q000652:urine; D015118:Eicosapentaenoic Acid / Q000096:biosynthesis* / Q000652:urine; D011464:Epoprostenol / Q000096:biosynthesis* / Q000031:analogs & derivatives; D006801:Humans; D007700:Kinetics; D008297:Male; D013058:Mass Spectrometry
chemical_list: D004041:Dietary Fats; D004281:Docosahexaenoic Acids; C034240:prostaglandin I3; D015118:Eicosapentaenoic Acid; D011464:Epoprostenol