Incorporation of conjugated linoleic acid isomers into porcine erythrocytes.

PURPOSE: The aim of the current study was to determine the incorporation of cis (c) 9, trans (t) 11-conjugated linoleic acid (CLA) and t10, c12-CLA into porcine erythrocytes-both isomers were supplemented in equal proportions. METHODS: The study group consisted of 16 piglets randomly assigned into experimental and control group. For the period of 5 weeks, the piglets from the experimental group were receiving a 1.2% CLA supplement while the controls were supplemented with the same amount of sunflower oil. For the remaining 7 weeks, the piglets were fed without a supplement. Blood samples to evaluate incorporation of CLA into erythrocyte membranes were taken from all animals on weekly basis. RESULTS: Compared to t10, c12-CLA isomer, proportion of c9, t11-CLA isomer in the membrane of erythrocytes was higher for the whole time of the study period. After 4 weeks of feeding, it approaches the plateau. The peak value for both isomers was measured at the end of week 5, with a value of 3.24 g c9, t11-CLA/100 g of fatty acids and a 1.09 g t10, c12-CLA/100 g of fatty acids (p < 0.0001). After cessation of supplementation, the proportion of both isomers gradually decreased to be almost completely washed out-in 7 weeks. CONCLUSIONS: During supplementation with equivalent amounts of CLA isomers, their proportion in membranes of porcine erythrocytes increases with time, with higher proportion of c9, t11-CLA. CLA isomers probably differently incorporate into different cell membranes at different species which could explain its various biological functions.

Influence of conjugated linoleic acid on the porcine immune response and morbidity: a randomized controlled trial.

BACKGROUND: Conjugated linoleic acid (CLA) has diverse influences on the immune response in different experimental models. In the present study we investigated the effect of CLA feeding on inflammatory and immune responses in a piglet model. We studied the duration of this effect and possible detrimental effects of CLA feeding. After 12 weeks of CLA and control supplementation and washout, animals were sacrificed and parenchymal organs were histologically examined. RESULTS: In activated peripheral mononuclear cells interferon-gamma was significantly (p = 0.008) lower in the CLA group by the end of the feeding period. This effect disappeared as soon as supplementation was stopped. No differences were found in the tumour necrosis factor-alpha, interleukin-10 production, serum immunoglobulin-G levels and fat infiltration of the liver, except that fat storage cell infiltration was significantly (p < 0.04) higher in the CLA-fed group. The effect of time for interferon-gamma, interleukin-10 and immunoglobulin-G levels was statistically significant. CONCLUSION: At the end of the feeding period the interferon-gamma response was depressed. However, the maturation of the piglet immune system in our young pig model probably outweighs the impact of CLA feeding on the immune response, even though liver fat storage cell infiltration, which plays an important role in liver regeneration, increased during CLA feeding of the piglets.

Fatty acid composition of lamb meat from the autochthonous Jezersko-Solcava breed reared in different production systems.

Thirty two autochthonous Jezersko-Solcava lambs were used to investigate the effect of production (pasture vs. stable) and weaning system (suckling vs. weaned) on fatty acid composition of Longissimus dorsi intramuscular fat in a 2 × 2 factorial design. Pasture lambs had lower intramuscular fat concentration (P<0.0001) more PUFA and trans C18:1, more ALA (P=0.0322), ARA (<0.0001) and EPA (0.0149) but less SFA (P<0.0001) than stable lambs. Weaning system affected PUFA (P=0.0040) and MUFA (P=0.0070) but not SFA and trans C18:1 fatty acids. The interaction of production system and weaning system was significant mainly for trans C18:1 and trans C18:2 fatty acids. Finally, lamb meat from all four treatments which are traditionally used in rearing of Jezersko-Solcava lambs are favourable from the nutritive point of view, due to their low n-6/n-3 ratio.