Trans Fatty Acids in Maternal Diet May Impair Lipid Biosynthesis in Mammary Gland of Lactating Rats

Although trans fatty acids are known to influence essential fatty acid (EFA) metabolism and serum levels of lipids and lipoproteins, little is known about their effects on the metabolism of mammary glands (MGs) during lactation. In this study, 5 groups of lactating Wistar rats were fed semisynthetic diets containing 7 % soy oil (control);7 % partially hydrogenated vegetable oil (7% PHVO);13% PHVO ₊7% soy oil (13% PHVO); 5% PHVO ₊2% soy oil (5% PHVO), and 3.5% PHVO ₊3.5% soy oil (3.5% PHVO). Dams were killed on the 12th day of lactation. Weight, lipid content (LC), in vivo lipogenesis rate (LR) and activity of the lipogenic (ATP-citrate lyase and malic) enzymes were evaluated in the MGs. Maternal food intake, weight gain, and total MG weight were not found to be significantly different between the groups. The groups with 13, 7 and 5 % PHVO presented a lower (p