Regulation of rat plasma and cerebral cortex oxylipin concentrations with increasing levels of dietary linoleic acid.
Linoleic acid (LA, 18:2n-6) is the most abundant polyunsaturated fatty acid in the North American diet and is a precursor to circulating bioactive fatty acid metabolites implicated in brain disorders. This exploratory study tested the effects of increasing dietary LA on plasma and cerebral cortex metabolites derived from LA, its elongation-desaturation products dihomo-gamma linolenic (DGLA, 20:3n-6) acid and arachidonic acid (AA, 20:4n-6), as well as omega-3 alpha-linolenic (α-LNA, 18:3n-3), eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). Plasma and cortex were obtained from rats fed a 0.4%, 5.2% or 10.5% energy LA diet for 15 weeks and subjected to liquid chromatography tandem mass spectrometry analysis. Total oxylipin concentrations, representing the esterified and unesterified pool, and unesterified oxylipins derived from LA and AA were significantly increased and EPA metabolites decreased in plasma at 5.2% or 10.5% energy LA compared to 0.4% energy LA. Unesterified plasma DHA metabolites also decreased at 10.5% energy LA. In cortex, total and unesterified LA and AA metabolites increased and unesterified EPA metabolites decreased at 5.2% or 10.5% LA. DGLA and α-LNA metabolites did not significantly change in plasma or cortex. Dietary LA lowering represents a feasible approach for targeting plasma and brain LA, AA, EPA or DHA-derived metabolite concentrations.
Department of Food Science and Technology, College of Agriculture and Environmental Sciences, University of California, Davis, CA, USA. Electronic address: ataha@ucdavis.edu.
Ameer Y
AY
Taha
Department of Food Science and Technology, College of Agriculture and Environmental Sciences, University of California, Davis, CA, USA.
Marie
M
Hennebelle
Department of Entomology and Nematology & UCD Comprehensive Cancer Center, University of California-Davis, Davis, CA, USA.
Jun
J
Yang
Department of Psychiatry, University of North Carolina-Chapel Hill, NC, USA.
Daisy
D
Zamora
Brain Physiology and Metabolism Section, Laboratory of Neuroscience, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA.
Stanley I
SI
Rapoport
Department of Entomology and Nematology & UCD Comprehensive Cancer Center, University of California-Davis, Davis, CA, USA.
Bruce D
BD
Hammock
Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA; Department of Physical Medicine and Rehabilitation, University of North Carolina-Chapel Hill, NC, USA.
Christopher E
CE
Ramsden
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D004041:Dietary Fats / Q000494:pharmacology*; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D019787:Linoleic Acid / Q000494:pharmacology*; D054883:Oxylipins / Q000097:blood*; D051381:Rats; D011916:Rats, Inbred F344
D004041:Dietary Fats; D054883:Oxylipins; D004281:Docosahexaenoic Acids; D019787:Linoleic Acid
Brain; High LA; Mediators; Metabolites; Omega-6 linoleic acid (LA); Oxylipin; Plasma