Polyunsaturated fatty acids roles

Chen, L.Y., Lawson, D.L., and Mehta, J.L. (1994) Reduction in Human Neutrophil Superoxide Anion Generation by n-3 Polyunsaturated Fatty Acids Role of Cyclooxygenase Products and Endothelium-Derived Relaxing Factor, Thromb. Res. 76,317-322. 

Kelly, F.J. (1991). The metabolic role of n-3 polyunsaturated fatty acids relationship to human disease. Comp. Biochem. Physiol. 23, 467-471. 

Elucidation of the physiological role of arachidonic acid 13 and other polyunsaturated fatty acids, particularly the role of all Z-4,7,10,13,16,19-decosahexaenoic acid 14, found in brain, required the corresponding stable-isotope labelled material1011. The deuteriated phosphonium salt 15, the key intermediate used in the synthesis of title compound 16 (equation 8), has been prepared in 19% overall yield12 starting with ethanol-D6 (equation 7). 

The capacity of P-oxidation in about 10% of that in the mitochondria but it plays an important role in oxidising unusual fatty acids for example, very long-chain fatty acids, polyunsaturated fatty acids, dicarbox-ylic fatty acids. 

Saturated fatty acids do not contain double bonds in the hydrocarbon chain. Unsaturated fatty acids contain from one to hve double bonds. Those with one double bond are known as monounsaturated, those with two as diunsatu-rated and those with more than two as polyunsaturated fatty acids. A brief summary of the roles of saturated and unsaturated fatty acids is given in Table 11.1. The proportion of these fatty acids in triacylglycerol in human adipose tissue is presented in Table 11.2. 

Although these are termed essential fatty acids, they are, in fact, precursors for the major polyunsaturated fatty acids that have essential roles in the body but are present only in small amounts in the diet. Linoleic acid is converted, via elongation and desaturation reactions, to dihomo-y-linolenic (20 3n-6) and then to arachidonic (20 4n-6) acid. a-Linolenic is converted to eicosapentaenoic (20 5n-3) and then docosahexae-noic (22 6n-3). The pathways for formation of these latter fatty acids, from their dietary precursors, are presented in Figures 11.11 and 11.12. Full details of one pathway are provided, as an example, in Appendix 11.4. For comparison of the two pathways, they are presented side by side in Figure 11.13. 

They act as local messengers in tissues and they provide communication between one cell type and another within a single tissue or an organ (i.e. they have a paracrine effect). They are synthesised from the polyunsaturated fatty acids that contain 20 carbons (e.g. arachidonate, eicosapentaenoic acids). These fatty acids are generated from the hydrolysis of membrane phospholipids by the activity of a phospholipase which releases the fatty acids from position 2 of the phospholipids. Their roles are described in detail below. 

Koletzko, B., Lien, E., Agostoni, C., Bohles, H., Campoy, C., Cetin, I., Decsi, T., Dudenhausen, J. W., and Dupont, C. (2008). The roles of long-chain polyunsaturated fatty acids in pregnancy, lactation and infancy Review of current knowledge and consensus recommendations. ]. Perinat. Med. 36, 5-14. 

Fatty acids are known to play an important role in signal transduction pathways via the inositol phosphate mechanism in both plants and animals. In animals, several polyunsaturated fatty acids like linolenic acid are precursors for hormones. Interruption of fatty acid... 

Jasmonic acid is an 18-carbon pentacyclic polyunsaturated fatty acid derived from lino-lenic acid, plays a role in plants similar to arachidonic acid,58 and has a structure similar to... 

Yehuda S, Rabinovitz S, Carasso RL, Mostofsky DI. 2002. The role of polyunsaturated fatty acids in restoring the aging neuronal membrane. Neurohiol Aging 23 843-853. 

Schoneich C, Asmus K-D (1990) Reaction of thiyl radicals with alcohols, ethers and polyunsaturated fatty acids a possible role of thiyl free radicals in thiol mutagenesis Radiat Environ Biophys 29 263-271... 

Kitajka K., Puskas L. G., Zvara A., Hackler L. J., Barcelo-Coblijn G., Yeo Y. K., and Farkas T. (2002). The role of n-3 polyunsaturated fatty acids in brain Modulation of rat brain gene expression by dietary n-3 fatty acids. Proc. Natl. Acad. Sci. USA 99 2619-2624. 

There were marked differences in the fatty acid patterns of the lipids of gills and kidneys, those from seawater fish possessing more w-3 in proportion to w-6 fatty acids and a higher proportion of total polyunsaturated fatty acids. They suggested that the role of polyunsaturates in membrane permeability and plasticity might account for the observation, and pointed out that the w-3 structure allows a greater degree of unsaturation than do the <0-6 or w-9 series. 

Bell, M.V., Henderson, R.J. and Sargent, J.R. (1986). The role of polyunsaturated fatty acids in fish. Comparative Biochemistry and Physiology 83B, 711-719. 

Pamova, P.G. (1986). Lipids of insecta. Long-chain polyunsaturated fatty acids and their functional role (In Russian). Zhumal Evolutsionnoy Biokhimii i Physiologii 22,74-83. 

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