Trans Fatty acids physiology

Despite the fact that trans fatty acids are unsaturated, their contributions to atherosclerosis are similar to those of saturated fats. This similarity in physiologic action can be attributed to which of the following ... 

Bauman, D.E., Lock A.L., Corl B.A., IpC., Salter A.M., Parodi P.W. 2005. Milk fatty acids and human health potential role of conjugated linoleic acid and trans fatty acids. In Ruminant Physiology Digestion, Metabolism and Impact of Nutrition on Gene Expression, Immunology and Stress. (K. Sejrsen, T. Hvelplund, and M.O. Nielsen, eds.), pp. 523-555, Wageningen Academic Publishers, Wageningen, The Netherlands. Academic Publishers. 

There is a vast amount of data on the effects different fatty acids have when fed as usual food lipids. These will not be dealt with here. It is sufficient to stress that it is important to avoid generalizations. All saturated fatty acids do not raise cholesterol. Not all polyunsaturated fatty acids reduce cholesterol, and the physiological effects of different trans-fatty acids are different. In general, each fatty acid has distinct effects. We concentrate here on how fat structure can modulate the known effects of fatty acids. Furthermore, it is important to keep in mind that the nutritional effects of edible fats and oils do not only depend on the fatty acids they contain but also on the presence of other components. 

Fritsche, J., and Steinhart, H. (1998) Analysis, Occurrence, and Physiological Properties of trans Fatty Acids (TFA) with Particular Emphasis on Conjugated Linoleic Acid Isomers (CLA)—A Review, Felt. Lipid 100,190-210. 

Fritsche, J. and Steinhart, H., Analysis, occurrence, and physiological properties of trans fatty acids (TFA) with particular emphasis on conjugated linoleic acid isomers (CLA)—A review, Fett/Lipid, 100, 190-210, 1998. 

The presence of cis rather than trans double bonds in unsaturated fatty acids ensures that lipids containing fatty acids have low melting points and are therefore fluid at physiological temperatures. 

Fatty acid carbon atoms are numbered starting at the carboxyl terminus, as shown in the margin. Carbon atoms 2 and 3 are often referred to as a and P, respectively. The methyl carbon atom at the distal end of the chain is called the co-carbon atom. The position of a double bond is represented by the symbol A followed by a superscript number. For example, cA-A means that there is a cis double bond between carbon atoms 9 and 10 trans-A. 2 means that there is a trans double bond between carbon atoms 2 and 3. Alternatively, the position of a double bond can be denoted by counting from the distal end, with the co-carbon atom (the methyl carbon) as number 1. An co-3 fatty acid, for example, has the structure shown in the margin. Fatty acids are ionized at physiological pH, and so it is appropriate to refer to them according to their carboxylate form for example, palmitate or hexadecanoate. 

Latruffe, N., M. Cherkaoui-Malki, V. Nicolas-Frances, B. Jannin, M.-C. Clemencet, F. Hansmannel, P. Passilly-Degrace and J.-P. Berlot. Peroxisome-proliferator-activated receptors as physiological sensors of fatty acid metabolism molecular regulation in peroxisomes. Biochem. Soc. Trans. 29 305-309, 2001. 

Sebedio, J.L. and Chardigny, J.M. 1996. Physiological effects of trans and cyclic fatty acids, in Deep Frying, Perkins, E.G. and Erickson, M.D., Eds., Champaign, IL AOCS Press, 183-209. 

Some bacterial cells contain mono-unsaturated fatty acids with a rran -confuguration as acyl components of membrane phospholipids. We found the temperature-dependent alteration in levels of a rran -mono-unsaturated fatty acid, 16 l(9t), in a psychrophilic bacterium, Vibrio sp. strain ABE-1 [1]. Morita et al. [2] presented the evidence for the direct in vivo isomerization between 16 l(9c) and 16 l(9t) in cells of this bacterium using stable isotope tracers, namely, [2,2-%2]16 l(9c) and [2,2-%2]16 l(9t). This isomerization is quite unique because of configurational isomerization of a double bond without shifting of the double bond position. In this article, we decribe purification and characterization of cis-trans isomerase from a psychrotrophic bacterium. Pseudomonas sp. strain E-3 Pseudomonas E-3), another organism that contains 16 l(9t) [1], and the possible physiological roles of rran -mono-unsaturated fatty acid in this bacterium. 

Keeney M (1970) Lipid metabohsm in the rumen. In PhUlipson AT (ed) Physiology of digestion and metabolism in the ruminant. Oriel Press, Newcastle, pp 489-503 Kemp P, Lander DJ (1984) Hydrogenation in vitro of a-hnolenic add to stearic acid by mixed cultures of pure strains of rumen bacteria. J Gen Microbiol 130 527-533 Kemp P, White RW, Lander DJ (1975) The hydrogenation of unsaturated fatty adds by five bacterial isolates from the sheep rumen, including a new spedes. J Gen Microbiol 90 100-114 Kepler CR, Tove SB (1967) Biohydrogenation of unsaturated fatty acids III. Purification trans-isomerase from Butyrivibrio fibrisolvens. J Biol Chem 242 5686-5692... 

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