Supplementation of long-chain polyunsaturated fatty acids (LCPUFAs) is advocated during pregnancy in some countries although very little information is available on their effects on placental ability to take up these fatty acids for fetal supply to which the fetal growth and development are critically dependent. To identify the roles of LCPUFAs on placental fatty acid transport function, we examined the effects of LCPUFAs on the uptake of fatty acids and expression of fatty acid transport/metabolic genes using placental trophoblast cells (BeWo). Following 24 h incubation of these cells with 100 microM of LCPUFAs (arachidonic acid, 20:4n-6, eicosapentaenoic acid, 20:5n-3, or docosahexaenoic acid, 22:6n-3), the cellular uptake of [(14)C] fatty acids was increased by 20-50%, and accumulated fatty acids were preferentially incorporated into phospholipid fractions. Oleic acid (OA, 18:1n-9), on the other hand, could not stimulate fatty acid uptake. LCPUFAs and OA increased the gene expression of ADRP whilst decreased the expression of ACSL3, ACSL4, ACSL6, LPIN1, and FABP3 in these cells. However, LCPUFAs but not OA increased expression of ACSL1 and ACSL5. Since acyl-CoA synthetases are involved in cellular uptake of fatty acids via activation for their channelling to lipid metabolism and/or for storage, the increased expression of ACSL1 and ACLS5 by LCPUFAs may be responsible for the increased fatty acid uptake. These findings demonstrate that LCPUFA may function as an important regulator of general fatty acid uptake in trophoblast cells and may thus have impact on fetal growth and development.