title: Increased dietary arachidonic acid enhances the synthesis of vasoactive eicosanoids in humans.
abstract: Data on the effect of dietary arachidonic acid (AA) (20:4n-6) on the synthesis of thromboxane and prostacyclin (PGI2) in humans are lacking. We measured the effect of 1.5 g/d (ca. 0.5 en%) of 20:4n-6 added isocalorically to a stabilization (low-AA) diet on the excretion of 11-dehydrothromboxane B2 (11-DTXB2) and 2,3-dinor-6-oxo-PGF1 alpha (PGI2-M). In a crossover design, 10 healthy men, living in a metabolic unit, were fed a diet (low-AA) containing 210 mg/d of 20:4n-6 for 65 d and an identical diet (high-AA) that contained 1.5 g/d of additional 20:4n-6 for 50 d. Three-day urine pools were collected at the end of each dietary period and analyzed for eicosanoids by gas chromatography-electron capture negative ion-tandem mass spectrometry. Mean excretion of 11-dehydrothromboxane B2 was 515 +/- 76, 493 +/- 154, and 696 +/- 144 ng/d (SD; n = 10) during the acclimation (15 d) low-AA diet and high-AA diet periods, respectively (41% increase from low-AA to high-AA diet, P = 0.0037); mean excretion of PGI2-M was 125 +/- 40, 151 +/- 36, and 192 +/- 55 ng/d (SD; n = 10) during acclimation (15 d) low-AA and high-AA diets; P = 0.0143). Thus both the metabolites of thromboxane and PGI2 increase on the high-AA diet. Furthermore, both indicated changes in metabolite excretion may be associated with measurable effects on several physiologically significant cellular functions, such as platelet aggregation in vivo and inflammation in response to immune challenges.
authors.affiliation: Nutrient Requirements and Functions Laboratory, Beltsville Human Nutrition Research Center, USDA, ARS, Maryland 20705, USA.
authors.forename: A
authors.initials: A
authors.lastname: Ferretti
authors.forename: G J
authors.initials: GJ
authors.lastname: Nelson
authors.forename: P C
authors.initials: PC
authors.lastname: Schmidt
authors.forename: D S
authors.initials: DS
authors.lastname: Kelley
authors.forename: G
authors.initials: G
authors.lastname: Bartolini
authors.forename: V P
authors.initials: VP
authors.lastname: Flanagan
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000031:analogs & derivatives / Q000652:urine; D000328:Adult; D016718:Arachidonic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D004041:Dietary Fats / Q000494:pharmacology*; D015777:Eicosanoids / Q000096:biosynthesis*; D011464:Epoprostenol / Q000378:metabolism; D005527:Food, Fortified; D006801:Humans; D008297:Male; D013928:Thromboxane A2 / Q000378:metabolism; D013929:Thromboxane B2 / Q000031:analogs & derivatives / Q000652:urine
chemical_list: D004041:Dietary Fats; D015777:Eicosanoids; D016718:Arachidonic Acid; D013929:Thromboxane B2; D013928:Thromboxane A2; D015121:6-Ketoprostaglandin F1 alpha; C028290:2,3-dinor-6-ketoprostaglandin F1alpha; C049235:11-dehydro-thromboxane B2; D011464:Epoprostenol