Effects of conjugated linoleic acid supplement on the composition of fatty acids, expressions of delta-5 desaturase (D5D) and fatty acid desaturase2 (FADS2) genes in mice.

摘要

The effects of conjugated linoleic acid (CLA) on the fatty acid composition of the plasma and liver and expression of delta-5 desaturase (DRD) and fatty acid desaturase2 (FADS2) genes in male mice using 2 different sources of dietary fat were investigated. Mice were divided into 4 groups and fed diets containing: beef tallow (BT); fish oil (FO); BT with CLA supplementation (BTC); and FO with CLA supplementation (FOC). Each group of 10 mice was fed the experimental diets for 4 wk. All the experimental diets contained 12% total dietary fat (w/w) either with or without 0.5% CLA (w/w). Fatty acid composition was analysed in the plasma and liver using GC. The levels of D5D and FADS2 expression were analysed by RT-PCR in the liver. Results showed that CLA participates competititively with C18:2 in the elongation and desaturation processes, leading to a significant increase in the levels of C20:4 and C22:6 in the BTC group (P < 0.05). Expression levels of DRD and FADS2 were higher in the BT and BTC group than in those of the FO and FOC groups; the expression of the DRD gene was greatly upregulated in the BTC group. Conversion ratios from C18:2 to C20:4 in the liver were higher in the BTC group than those in other groups. Results suggest that increased expression of D5D and FADS2 genes may be responsible for the enhanced CLA effects on the desaturation in the BT containing fatty acids rather than the FO rich in n-3 PUFA.