CONICET | Buscador de Institutos y Recursos Humanos

Placental transfer of maternal dietary essential fatty acids is needed for fetal growth and development. These long-chain polyunsaturated fatty acids are ligands of peroxisome proliferators activated receptors (PPARs), transcription factors that regulate lipid metabolism in many tissues. The aim of this work was to evaluate lipid metabolism in the feto-placental unit of rats fed with diets supplemented with olive oil (OO) or safflower oil (SO), which respectively contain 75% monounsaturated and 75% polyunsaturated fatty acids. Methods: Control (C) and streptozotocin-induced diabetic (D) rats were treated with the OO (6%) or SO (6%) from day 1 to day 13.5 of pregnancy, when fetuses and placentas were explanted. Lipid levels: triglycerides (TG), cholesteryl esters (CE), cholesterol (CHO) and phospholipids (PL) were analysed by TLC and densitometry. The de novo lipid synthesis was evaluated by 14C-acetate incorporation to lipids. Results: SO treatment did not modify lipid levels in C placentas and fetuses. In D rats, SO increased CE (p<0.05) and TG (p<0.01) levels in the placenta and PL levels (p<0.05) in the fetuses as compared to OO. SO decreased the synthesis of CE (p<0.05), CHO (p<0.05) and PL (p<0.05) in C and D placentas, while it increased the synthesis of all lipid species analyzed in C fetuses (p<0.05) and the synthesis of CE (p<0.01) and TG (p<0.05) in D fetuses. Conclusions: Treatment with a diet supplemented with polyunsaturated fatty acids changes lipid metabolism in the rat feto-placental unit. Differences in dietary responses in the diabetic group may rely on alterations in the levels and/or function of PPAR isoforms and will require further analysis.