The Lipogenic Gene Expression of Mammary was Inhibited by CLA in Lactating Mice

In order to test the lipogenic gene expression of mammary gland in lactating animal which received the CLA, mice are housed individually in polycarbonate cages. All animals were fed the laboratory chow diet for the first 3 d.On day 4 postpartum,six lactating mice were randomly assigned to the control group (2% Peanut oil) or low lever CLA groups (LL group,0.5% CLA +1.5% Peanut oil); median lever CLA group (ML group, 1%CLA+1% Peanut oil); high lever CLA group (HL group, 1.5%CLA+0.5% Peanut oil) from day 4 to 15 postpartum. The body weight and food intake of dam and body weight of pup was tested every day. The weight and composition of Milk were measured by the chemistry method. The mRNA expression of lipogenic gene was measured using real-time PCR.The results showed that dam body weight didn´t changed through the testing period, but the food significantly decreased of HL group compared with control group(13.75 vs 19.45),After the intake of CLA food,The pups of HL group lost weight more rapidly, and from d 8 had significantly lower body weights than control pups (P<;0.01) .The milk weight obtained from the stomach ranged between 0·94to 0·55 g/suckling pup. The milk lipid concentration of HL group was significantly lower than control(10.82 vs 15.42, p=0.003).There were no differences in the protein and lactose concentrations of milk from CLA and control groups. mRNA expression ratio of ACC,SCD,LPL,FASN gene were significantly down-regulated in mammary tissue in HL group compared with control (p<;0.05).The regulators of SREBP mRNA gene expression was also down-regulated in mammary tissue in HL group compared with control group. In the present study,Our results shows that CLA ingestion during lactation decreased the synthesis of lipids in the mammary gland of mice.