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.