%0 Journal Article %T Absorption and metabolism of conjugated ¦Á-linolenic acid given as free fatty acids or triacylglycerols in rats %A M¨¦lanie Plourde %A Jean-Pierre Sergiel %A Jean-Michel Chardigny %A St¨¦phane Gr¨¦goire %A Paul Angers %A Jean-Louis S¨¦b¨¦dio %J Nutrition & Metabolism %D 2006 %I BioMed Central %R 10.1186/1743-7075-3-8 %X Male Wistar rats were fed rumenic acid (RA: cis-9,trans-11 18:2) and a CLnA mixture (cis-9,trans-11,cis-15 18:3 and cis-9,trans-13,cis-15 18:3) as FFA and TAG for 8 days. RA and CLnA were both totally absorbed when given as FFA as well as TAG. Both isomers of CLnA as FFA or TAG were incorporated into neutral lipids. Metabolites up to 22:6 conjugated isomers were present in liver and plasma phospholipids of rats fed the CLnA diets.Finally, CLnA are as well absorbed as RA in vivo and their incorporation into tissues and bioconversion are similar when ingested as FFA or as TAG.Conjugated linoleic acid (CLA) is a group of polyunsaturated fatty acids (PUFA) found in ruminant meat (about 0.4% of the total lipids) and milk products (about 1% of the total lipids) with a conjugated double bonds system [1]. Among the CLA family, rumenic acid (RA), cis-9,trans-11 18:2 is the major conjugated isomer found in ruminant fat. Many health benefits have been attributed to RA isomers like inhibition of carcinogenesis in rats [2] whereas CLA mixtures have demonstrated abilities to modulate atherosclerotic plaque formation in rabbits and hamsters [3,4] and to decrease body fat mass in mice [5]. Although many investigations were done regarding prevention of diseases, few studies have investigated the impact of the ingested CLA form (FFA, TAG or FAME) on tissue metabolism and absorption [6]. In this respect, Fernie et al. [6] showed that CLA absorption in humans as FFA and TAG is similar as illustrated by their occurrence into chylomicrons, while the absorption was lower for fatty acid methyl esters.Conjugated alpha linolenic acid (CLnA) is another group of PUFA. One isomer has recently been reported in milk fat at a level of about 0.03% of total fatty acids [7]. The cis-9,trans-11,cis-15 18:3 isomer results from the biohydrogenation of ¦Á-linolenic acid. The cis-9,trans-11,cis-15 18:3 isomer combines the conjugated double bond system of RA and the n-3 double bond of ¦Á-linolenic acid (Figu %U http://www.nutritionandmetabolism.com/content/3/1/8