title: Comparison of the transport characteristics of bioactive substances in IUGR and normal placentas.
abstract: Knowing that IUGR is associated with altered placental transport, we aimed to characterize the placental transport of folic acid (FA), thiamine (THIAM), serotonin (5-HT), and 1-methyl-4-phenylpyridinium (MPP+) in IUGR. For this, we compared the transport characteristics of (3)H-FA, (3)H-THIAM, (3)H-5-HT, and (3)H-MPP+ in primary cultured human cytotrophoblasts isolated from IUGR and normal placentas (GRTB and NTB cells, respectively) and quantified mRNA expression of several placental transporters, by real-time RT-PCR. Our results show that GRTB cells take up (3)H-FA more efficiently (higher k(in) and A(max) values) and have higher transport capacity (higher V(max) values) for (3)H-FA, (3)H-5-HT, and (3)H-MPP+, when compared with NTB cells. In addition, GRTB cells take up (3)H-THIAM with higher affinity and (3)H-MPP+ with lower affinity than NTB cells. Finally, IUGR placentas have a generalized increase in mRNA expression of FA, THIAM, 5-HT, and MPP+ transporters, when compared with normal placentas, suggesting that the increase in transport capacity may be due to increased expression of placental transporters. These results point to an effect of "compensation for the weakness" of the IUGR placenta and pose the placenta as an active mediator of the communication between maternal and fetal environments.
authors: Department of Biochemistry (U38/FCT), Faculty of Medicine, University of Porto, Porto, Portugal. keating@med.up.pt
authors: Elisa
authors: E
authors: Keating
authors: Pedro
authors: P
authors: Gonçalves
authors: Fernanda
authors: F
authors: Costa
authors: Isabel
authors: I
authors: Campos
authors: Maria João
authors: MJ
authors: Pinho
authors: Isabel
authors: I
authors: Azevedo
authors: Fátima
authors: F
authors: Martel
mesh_terms: D015655:1-Methyl-4-phenylpyridinium / Q000378:metabolism; D001692:Biological Transport; D002478:Cells, Cultured; D005260:Female; D005317:Fetal Growth Retardation / Q000378:metabolism*; D005492:Folic Acid / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism; D013831:Thiamine / Q000378:metabolism; D014327:Trophoblasts / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D012701:Serotonin; D005492:Folic Acid; D015655:1-Methyl-4-phenylpyridinium; D013831:Thiamine