Effects Of Dietary Conjugated Linoleic Acid On Mammary Lipid Metabolism And Lipogenic Gene Expression In Lactating Mouse

CLA (Conjugated linoleic acid, CLA), is one of the natural active substances discoveried in recent years, has a series of important physiological functions ,can resist cancer, improve immunity, reduce fat synthesis, control diabetes.The present study was conducted to investigate the biological activities of CLA and dietary regulation on conjugated linoleic acid content of animal products , but the exact molecular mechanism of action has not been completely elucidated .This study selected 24 healthy Kunming lacting mice,which were randomly divided into four groups, n = 6, fed with different doses of CLA from d 6 to 10 postpartum to test the maternal food intake, maternal weight, milk composition and litter weight change, as well as lipogenic gene expression by real-time fluorescence quantitative PCR. The results showed that: compared with the control, maternal feed intake of high dose group reduced significantly (P<0.05), Milk fat percentage was decreased about 8.1%( low-dose group), about 12.6%(middle dose group) and the high dose group decreased about 29.8%, reached a significant level (P= 0.003), but milk protein, lactose content in each group had no significant difference; The growth rate of pups from mice fed high dose group CLA was slower (P < 0.05) compared with other treatment groups,control group pups was 71.60g, and the high dose group was 49.93g(P =0.001) on the 14d postpartum; Lipogenic genes measured included Acetyl-CoA carboxylase(ACC), Stearoyl-CoA desaturase(SCD), Fatty acid synthase(FAS), and regulatory factors peroxisome proliferator activated receptors (PPAR), sterol response element binding proteinsSREBP.mRNA abundance changed, compared with the control group, ACC, FAS, SCD gene expression of high dose group reduced significantly (P<0.05), Showed that CLA reduced the expression of mammary gland fatty acid synthase.,regulatory factor PPAR, SREBP gene expression was also significantly reduced(P<0.05) , showed that PPAR and SREBP as a factor of regulation of fatty acid synthase that may lead to the milk fat decreased .