Differential Long-Chain Polyunsaturated Fatty Acids Status and Placental Transport in Adolescent Pregnancies.

Adolescent pregnancy increases risk of adverse perinatal outcomes. Placental delivery of long-chain polyunsaturated fatty acids (LCPUFA) is essential for fetal growth and development. In this pilot study, we aimed to assess maternal and fetal status of fatty acids (FA) measured at birth and the expression of key genes involved in FA uptake, transport and metabolism in the placenta of fifteen adolescents and fifteen adults. FA were quantified by gas-liquid chromatography. Placental expression of FA transporters was assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and peroxisome proliferator-activated receptor gamma (PPARγ) was quantified by Western Blot. Adolescents had lower docosahexaenoic acid (DHA, 22:6 n-3) and total n-3 FA levels in maternal erythrocytes and placenta, but these were not different in fetal erythrocytes. Arachidonic acid (AA, 20:4 n-6) concentration was increased in placenta but lower in fetal circulation. Plasma membrane fatty acid binding protein (FABPpm) and fatty acid transport protein (FATP) 4 mRNA expressions were not different, however FATP1, fatty acid translocase (FAT/CD36) and fatty acid binding protein 3 (FABP3) mRNA and PPARγ protein levels were decreased in placenta of adolescents. Despite significant downregulation of FATP1, CD36 and FABP3, there was only a modest decrease in LCPUFA (10%) and AA (12%) and no difference in DHA content in cord blood, suggesting that FA transfer to the fetus was partially protected by other factors in adolescents from this cohort.

Effect of variation of trans-fatty acid in lactating rats' diet on lipoprotein lipase activity in mammary gland, liver, and adipose tissue.

OBJECTIVE: Lactation is associated with an increase in lipoprotein lipase (LPL) activity in the mammary gland (MG) and a decrease in adipose tissue because lactation redirects circulating substrates to the MG for milk synthesis. We investigated the effects of different dietary contents of trans-fatty acid (TFA) on LPL activity in maternal tissues and fatty acid composition in milk. METHODS: Lactating rats were fed semisynthetic isocaloric diets containing 7% soy oil (control), 7% partially hydrogenated vegetable oil (7%-PHVO), 5% PHVO plus 2% soy oil (5%-PHVO), or 3.5% PHVO plus 3.5% soy oil (3.5%-PHVO). On lactation day 14, animals were decapitated and MG, liver, and parametrial adipose tissue were extracted to determine total lipid contents, percentages of TFA, and LPL activity. Milk lipid composition was examined by gas chromatographic analysis of the gastric content of 14-d-old suckling pups. RESULTS: Maternal consumption of TFA increased dietary TFA incorporation in MG and liver and decreased it in parametrial adipose tissue. Diets with higher trans concentrations (7%-PHVO) significantly increased lipid content in the MG, and all groups fed trans-based diets showed significant increases in LPL activity in the MG. Although LPL increased in the MG, milk of rats fed TFA-based diets had significant decreases in the percentage of essential fatty acids. CONCLUSIONS: TFA intake during lactation alters maternal lipid metabolism and the percentage of essential fatty acids in milk; therefore, it is important to alert the population to avoid excessive intake of TFAs during lactation.

Efeitos das dietas com diferentes concentrações de ácidos graxos trans no metabolismo lipídico de ratas lactantes / Effects of diets with differents quantities of hydrogenated vegetal fat on the lipidic metabolism of rats during lactation

Durante os últimos anos várias pesquisas apontam para os riscos, sob o ponto de vista da saúde humana, do consumo de ácidos graxos trans. Estes ácidos são encontrados, na sua grande maioria, nas gorduras vegetais parcialmente hidrogenadas, utilizadas em alimentos industrializados. Existem poucas informações a respeito das alterações metabólicas que ocorrem no organismo materno, causadas pela ingestão de ácidos graxos trans (AGT) durante a lactação. O presente estudo objetivou avaliar os efeitos das dietas com diferentes quantidades de gordura vegetal parcialmente hidrogenada (GVPH), rica em AGT, sobre o metabolismo lipídico na lactação. Utilizou-se ratas lactantes da linhagem Wistar, que foram divididas nos seguintes grupos: Grupo Controle - ratas que receberam ração a base de caseína com 7 por cento de óleo de soja; Grupo 7 por cento GVPH - que receberam ração a base de caseína e 7 por cento de gordura vegetal parcialmente hidrogenada; Grupo 3,5 por cento - receberam ração a base de caseína e 3,5 por cento de gordura vegetal parcialmente hidrogenada mais 3,5 por cento de óleo de soja; Grupo 5 por cento - receberam ração a base de caseína e 5 por cento de gordura vegetal hidrogenada mais 2 por cento de óleo de soja; Grupo 13 por cento de GVPH - receberam ração a base de caseína e com 7 por cento de óleo de soja e 13 por cento de gordura vegetal hidrogenada. No décimo quarto dia de lactação os animais receberam injeção intraperitoneal de 0,3 mCi de 3H2O e 1 (uma) hora depois foram decapitados. O sangue foi coletado para obtenção do plasma e retirados e pesados os tecidos maternos: glândula mamária (GM), fígado (FIG) e tecido adiposo parametrial (TAP) para determinação do conteúdo total de lipídios e da taxa de lipogênese in vivo. Foram avaliados também nestes tecidos: o percentual de ácidos graxos trans, a atividade da enzima lípase lipoprotéica e das enzimas lipogênicas Málica e ATP-citrato liase...