Selenite, selenized yeast, or conjugated linoleic acid isomers supplemented to the diet influence the fatty acid profile in the spleen and blood plasma of rats

The effect of dietary conjugated linoleic acid (CLA) isomers (CLAmix), Na2SeO3 (SelV) or selenized yeast (SeY) on spleen weight, contents of CLA isomers and other fatty acids (FA), and efficiency of fatty acid desaturation in the spleen and blood plasma of rats were investigated. The study was performed on 80 female Wistar rats, 8 weeks of age with an initial body weight of 195.4 +/- 0.8 g. Each group numbered 8 rats. For 6 weeks the rats were fed ad libitum the Labofecd I-1 diet supplemented with 1.5% CLAmix, 0.2 ppm Se as sodium selenite ((L)SelV), selenized yeast (LSeY), or 0.5 ppm Se as SeIV ((H)SelV) or SeY (HSeY). The addition of CLAmix to the diet with SeIV or (H)SelV increased the weight of the spleen in comparison with rats fed the diet with SeIV or the control group. The diets enriched in CLAmix, HSeY, or the diet with CLAmix and SeY (as LSeY or HSeY) decreased spleen weight. The diet containing CLAmix, with or without Se, as SeIV or SeY, reduced the sum of fatty acids (FA) in the spleen, while increasing it in the plasma. The diet with CLAmix and HScY most efficiently increased the content of CLA isomers, especially c9t11CLA, in the spleen and plasma. C9t11CLA in the spleen was metabolized more efficiently than t10cl2CLA, while in plasma tl0c12CLA was metabolized faster than c9tllCLA. The diet containing CLAmix with or without SeIV or SeY, significantly decreased the contents of c9C18:1, cllC18:1, and sums of saturated fatty acids (SFA), mono-(MUFA) and polyunsaturated fatty acids (PUFA) in the spleen, whereas the diet containing CLAmix and/or HSeY increased the concentrations of these fatty acids in plasma. The diet enriched in CLAmix or HSeY decreased the ratios of PUFA/SFA, MUFA/SFA and PUFA/Sigma FA in the spleen and plasma. The addition of SelV or SeY to the diet with CLAmix usually slightly decreased these ratios in the spleen and plasma in comparison with the diet containing CLAmix. Our results indicate that the diet with CLAmix more significantly stimulated the metabolism of PUFA and MUFA in the spleen than of SFA. The addition of SeIV or SeY to the diet with CLAmix increased the metabolic efficiency of PUFA and MUFA in the spleen.