title: The effect of linoleic, arachidonic and eicosapentaenoic acid supplementation on prostacyclin production in rats.
abstract: We examined the effect of dietary supplementation of linoleic acid (LA), arachidonic acid (AA) or eicosapentaenoic acid (EPA) to rats fed a diet low in linoleic acid on in vitro and in vivo production of prostacyclin. Male Sprague Dawley rats were fed a high-fat diet (50% energy as fat, 1.5% linoleic acid) for two weeks. Three of the groups were then supplemented orally with either 90 mg/d of LA, AA or EPA, all as the ethyl esters, for a further two weeks while remaining on the high-fat diet. Forty-eight hour urine samples were collected at the end of the second and fourth weeks. In vivo prostacyclin production was determined by a stable isotope dilution, gas chromatography/mass spectrometry assay for the major urinary metabolite of prostacyclins (2,3-dinor-6-keto-PGF1 alpha or PGI2-M and delta 17-2,3-dinor-6-keto-PGF1 alpha or PGI3-M). In vitro prostacyclin production was determined by radioimmunoassay of the stable metabolite (6-keto-PGF 1 alpha) following incubation of arterial tissue. Oral supplementation with AA resulted in a rise in plasma and aorta 20:4n-6, and increased in vitro prostacyclin and urinary PGI2-M production. EPA supplementation resulted in a rise in plasma and aorta 20:5n-3 and 22:5n-3, and a decline in plasma 20:4n-6, but not in the aorta. In the EPA-supplemented group, the in vitro prostacyclin and the urinary PGI3-M increased, but urinary PGI2-M decreased. The increase in in vitro prostacyclin production in the EPA-supplemented rats was unexpected and without obvious explanation.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: School of Nutrition and Public Health, Deakin University, Geelong, Victoria, Australia.
authors.forename: N J
authors.initials: NJ
authors.lastname: Mann
authors.forename: G E
authors.initials: GE
authors.lastname: Warrick
authors.forename: K
authors.initials: K
authors.lastname: O'Dea
authors.forename: H R
authors.initials: HR
authors.lastname: Knapp
authors.forename: A J
authors.initials: AJ
authors.lastname: Sinclair
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000737:chemistry; D016718:Arachidonic Acid / Q000494:pharmacology*; D004041:Dietary Fats / Q000494:pharmacology; D015118:Eicosapentaenoic Acid / Q000494:pharmacology*; D011464:Epoprostenol / Q000096:biosynthesis* / Q000652:urine; D005227:Fatty Acids / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D066298:In Vitro Techniques; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000494:pharmacology*; D008297:Male; D010743:Phospholipids / Q000097:blood / Q000737:chemistry; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D008041:Linoleic Acids; D010743:Phospholipids; D016718:Arachidonic Acid; D019787:Linoleic Acid; D015118:Eicosapentaenoic Acid; D011464:Epoprostenol