All fatty acids have important functions, but the term “essential” is applied only to those polyunsaturated fatty acids (PUFA) that are necessary for good health and cannot be completely synthesized in the body. The need for arachidonic acid, which is utilized for eicosanoid synthesis and is a constituent of membrane phospholipids involved in signal transduction, is the main reason why the n-6 class of PUFA are essential. Physiological data indicate that n-3 PUFA also are essential. Although eicosapentaenoic acid also is a substrate for eicosanoid synthesis, docosahexaenoic acid (DHA) is more likely to be the essential n-3 constituent because it is necessary for optimal visual acuity and neural development. DHA is present in large amounts in the ethanolamine and serine phospholipids, suggesting that its function involves membrane structure. Because the metabolism of n-6 PUFA is geared primarily to produce arachidonic acid, only small amounts of 22-carbon n-6 PUFA are ordinarily formed. Thus, the essentiality of n-3 PUFA may be due to their ability to supply enough 22-carbon PUFA for optimal membrane function rather than to a unique biochemical property of DHA.
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- n-6 DPA:
n-6 docosapentaenoic acid
polyunsaturated fatty acid(s)
Connor, W.E., Neuringer, M., and Reisbeck, S. (1992) Essential Fatty Acids: The Importance of n-3 Fatty Acids in the Retina and Brain,Nutr. Rev. 50, 21–29.
Uauy, R.D., Birch, E.E., Birch, D.G., and Peirano, P. (1992) Visual and Brain Function Measurements in Studies of ω-3 Fatty Acid Requirements in Infants,J. Pediatr. 120s, 168–180.
Smith, W.L., Borgeat, P., and Fitzpatrick, F.A. (1991) The Eicosanoids: Cyclooxygenase, Lipoxygenase, and Epoxygenase Products, inBiochemistry of Lipids, Lipoproteins and Membranes (Vance, D.E., and Vance, J., eds.), Elsevier, Amsterdam, pp. 297–325.
Dudley, D.T., Macfarlane, D.E., and Spector, A.A. (1987) Depletion of Arachidonic Acid from GH3 Cells,Biochem. J. 246, 669–680.
Downing, D.T. (1992) Lipid and Protein Structures in the Permeability Barrier of Mammalian Epidermis,J. Lipid Res. 33, 301–313.
Yerram, N.R., Moore, S.A., and Spector, A.A. (1989) Eicosapentaenoic Acid Metabolism in Brain Microvessel Endothelium: Effect on Prostaglandin Formation,J. Lipid Res. 30, 1747–1757.
Yerram, N.R., and Spector, A.A. (1989) Effects of Omega-3 Fatty Acids on Vascular Smooth Muscle Cells: Reduction in Arachidonic Acid Incorporation into Inositol Phospholipids,Lipids 24, 594–602.
Williard, D.E., Kaduce, T.L., Harmon, S.D., and Spector, A.A. (1998) Conversion of Eicosapentaenoic Acid to Chain-Shortened Omega-3 Fatty Acid Metabolites by Peroxisomal Oxidation,J. Lipid Res. 39, 978–986.
Yorek, M.A., Bohnker, R.R., Dudley, D.T., and Spector, A.A. (1984) Comparative Utilization of n-3 Polyunsaturated Fatty Acids by Cultured Human Retinoblastoma Cells,Biochim. Biophys. Acta 795, 277–285.
Dudley, D.T., and Spector, A.A. (1986) Inositol Phospholipid Arachidonic Acid Metabolism in GH3 Pituitary Cells,Biochem. J. 236, 235–242.
Applegate, K.R., and Glomset, J.A. (1991) Effect of Acyl Chain Unsaturation on the Conformation of Model Diacylglycerols: a Computer Modeling Study,J. Lipid Res. 32, 1635–1644.
Hyman, B.T., and Spector, A.A. (1982) Choline Uptake in Cultured Human Y79 Retinoblastoma Cells: Effects of Polyunsaturated Fatty Acid Compositional Modifications,J. Neurochem. 38, 650–656.
Yorek, M.A., Hyman, B.T., and Spector, A.A. (1983) Glycine Uptake by Cultured Human Y79 Retinoblastoma Cells: Effect of Changes in Phospholipid Fatty Acyl Unsaturation,J. Neurochem. 40, 70–78.
Yorek, M.A., Strom, D.K., and Spector, A.A. (1984) Effect of Membrane Polyunsaturation on Carrier-Mediated Transport in Cultured Retinoblastoma Cells: Alterations in Taurine Uptake,J. Neurochem. 41, 809–815.
Poling, J.S., Karanian, J.W., Salem, N., Jr., and Vicini, S. (1995) Time- and Voltage-Dependent Block of Delayed Rectifier Potassium Channels by Docosahexaenoic Acid,Molec. Pharmacol. 47, 381–390.
Litman, B.J., and Mitchell, D.C. (1996) A Role for Phospholipid Polyunsaturation in Modulating Membrane Protein Function,Lipids 31, S–193-S–197.
North, J.A., Spector, A.A., and Buettner, G.R. (1994) Cell Fatty Acid Composition Affects Free Radical Formation During Lipid Peroxidation,Am. J. Physiol. 267, C177-C188.
Jump, D.B., Clarke, S.D., Thelen, A., Liimatta, M., Ren, B., and Badin, R. (1996) Dietary Polyunsaturated Fatty Acid Regulation of Gene Expression,Prog. Lipid Res. 35, 227–241.
Rotstein, N.P., Aveldano, M.I., Barrantes, F.J., Roccamo, A.M., and Politi, L.E. (1997) Apoptosis of Retinal Photoreceptors During Developmentin vitro: Protective Effect of Docosahexaenoic Acid,J. Neurochem. 69, 504–513.
Sprecher, H., Luthria, D.L., Mohammed, B.S., and Baykousheva, S.P. (1995) Reevaluation of the Pathways for the Biosynthesis of Polyunsaturated Fatty Acids,J. Lipid Res. 36, 2471–2477.
Moore, S.A., Yoder, E., Murphy, S., Dutton, G.R., and Spector, A.A. (1991) Astrocytes, Not Neurons, Produce Docosahexaenoic Acid (22:6n-3) and Arachidonic Acid (20:4n-6),J. Neurochem. 56, 518–524.
Spector, A.A., and Moore, S.A. (1992) Role of Cerebromicrovascular Endothelium and Astrocytes in Supplying Docosahexaenoic Acid to the Brain, in:Essential Fatty Acids and Eicosanoids (edited by Sinclair, A., and Gibson, R.) American Oil Chemists’ Society, Champaign, pp. 100–103.
Zhang, H., Hamilton, J.H., Salem, N. Jr., and Kim, H.-Y. (1998) n-3 Fatty Acid Deficiency in the Rat Pineal Gland: Effects on Phospholipid Molecular Species Composition and Endogenous Levels of Melatonin and Lipoxygenase Products, J.Lipid Res. 39, 1397–1403.
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Spector, A.A. Essentiality of fatty acids. Lipids 34, S1–S3 (1999). https://doi.org/10.1007/BF02562220
- Arachidonic Acid
- Essential Fatty Acid
- Docosahexaenoic Acid
- Docosapentaenoic Acid
- Retinoblastoma Cell