Dietary trans-vaccenic acid (trans11-18:1) increases concentration of cis9,trans11-conjugated linoleic acid (rumenic acid) in tissues of lactating mice and suckling pups

Abstract

-Lactating mice were fed trans-vaccenic acid (trans11-18:1, TVA) to assess desaturation of TVA to cis9,trans11-conjugated linoleic acid (9/11CLA). Diets contained 30 g . kg -1 18:2n-6 (LA) or 20 g LA plus 10 g 18:0 (SA), TVA, or a CLA mixture (MCLA). Compared with SA, feeding TVA increased 9/11CLA concentrations in blood plasma phospholipid, triglyceride, and free fatty acid fractions. However, concentrations of 9/11CLA in plasma fractions were greater when MCLA was fed compared with SA or TVA. No 9/11CLA was detected in liver of mice fed SA, and it was only 1 mg . g -1 of total fatty acids in the carcass. In contrast, 9/11CLA content of liver (5 mg . g -1 ) and carcass (6 mg . g -1 ) of mice fed TVA was similar to liver (5 mg . g -1 ) and carcass (7 mg . g -1 ) of mice fed MCLA. Mammary tissue of SA-fed mice had no detectable 9/11CLA, compared with 5 or 14 mg . g -1 for TVA or MCLA-fed mice. Stearoyl-CoA desaturase activity in mammary tissue from TVA-fed dams was 14% greater compared with SA. Activity of this enzyme in liver tissue was similar among treatments. In pups nursing TVA-fed dams, 9/11CLA accounted for 3 mg . g -1 in liver but no 9/11CLA was detected in the carcass. In pups nursing MCLA-fed dams, however, 9/11CLA accounted for 8 and 6 mg . g -1 in liver and carcass. Results indicated TVA desaturation enhanced 9/11CLA in tissues and milk fat. stearoyl-CoA desaturase / trans-vaccenic acid / rumenic acid / milk fatRésumé -L'acide trans-vaccénique (trans11-18:1) alimentaire augmente la concentration de l'acide linoléique conjugué (acide ruménique, cis9, t rans11-18:2) dans les tissus de la souris allaitante et du souriceau. Des souris allaitantes ont reçu de l'acide trans-vaccénique (trans11-18:1, TVA) afin de démontrer la désaturation du TVA en acide linoléique conjugué cis9,trans11-18:2 (9/11CLA). Des régimes contenant 30 g . kg -1 d'acide linoléique (18:2n-6, LA) ou 20 g de LA plus Reprod. Nutr. Dev. 42 (2002) 85-99 85

Fatty acid profiles in tissues of mice fed conjugated linoleic acid

“…This is in agreement with observations in rat liver [16] and in blood plasma from lactating mice [17]. Similar to VA, CLA was also preferably incorporated into TAG.…”

Conjugated linoleic acids: all the same or to everyone its own function?

“…Some of the rumenic acid formed escapes total hydrogenation and is taken up by the intestines and reaches milk and muscle lipids. Transvaccenic acid (18 carbons long, one transdouble bond located in the D-11 position, another by-product of the biohydrogenation reaction), can also undergo delta-9 desaturation in the intestines, liver, mammary gland, and adipose tissue, and there it forms rumenic acid endogenously [25] (Fig.1). In humans, trans-vaccenic acid occurring from the intake of ruminant products can be similarly converted to the 9c,11t-isomer [1,48], This comes in addition to the daily 200-400 mg of pre-formed ingested rumenic acid [15].…”

Conjugated Linoleic and Linolenic Acid Production by Bacteria: Development of Functional Foods

“…CLNA content in milk is around of 0.3-0.39 mg/g fat [23,40]. At the present, the effect of diet on CLNA concentration in milk was only reported by one work, where cows not fed with extruded linseed (control) have no CLNA in milk, but linseed supplementation in diet increased both CLA and CLNA content, reaching the latest fatty acid a value of 0.15% of total fatty acids [22].…”

“…Respect to CLA synthesis in non-ruminant animal, an increase on CLA content in tissues was evidenced in studies using rats [35] and mice [23] after TVA supplementation.…”

“…All conjugated fatty acids are absorbed by intestine cells, reason why they are further present in milk and meat fat [22][23]. [17]) and endogenous synthesis of CLA in mammary gland (dotted arrow).…”