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Göteborgs universitets publikationer

Human placental taurine transporter in uncomplicated and IUGR pregnancies: cellular localization, protein expression, and regulation

Författare och institution:
Sara Roos (Institutionen för fysiologi och farmakologi, Avdelningen för fysiologi); Theresa L Powell (Institutionen för fysiologi och farmakologi, Avdelningen för fysiologi); Thomas Jansson (Institutionen för fysiologi och farmakologi, Avdelningen för fysiologi)
Publicerad i:
Am J Physiol Regul Integr Comp Physiol, 287 ( 4 ) s. R886-93
Artikel, refereegranskad vetenskaplig
Sammanfattning (abstract):
Transplacental transfer is the fetus' primary source of taurine, an essential amino acid during fetal life. In intrauterine growth restriction (IUGR), placental transport capacity of taurine is reduced and fetal taurine levels are decreased. We characterized the protein expression of the taurine transporter (TAUT) in human placenta using immunocytochemistry and Western blotting, tested the hypothesis that placental protein expression of TAUT is reduced in IUGR, and investigated TAUT regulation by measuring the Na(+)-dependent taurine uptake in primary villous fragments after 1 h of incubation with different effectors. TAUT was primarily localized in the syncytiotrophoblast microvillous plasma membrane (MVM). TAUT was detected as a single 70-kDa band, and MVM TAUT expression was unaltered in IUGR. The PKC activator PMA and the nitric oxide (NO) donor 3-morpholinosydnonimine decreased TAUT activity (P < 0.05, n = 7-15). However, none of the tested hormones, e.g., leptin and growth hormone, altered TAUT activity significantly. PKC activity measured in MVM from control and IUGR placentas was not different. In conclusion, syncytiotrophoblast TAUT is strongly polarized to the maternal-facing plasma membrane. MVM TAUT expression is unaltered in IUGR, suggesting that the reduced MVM taurine transport in IUGR is due to changes in transporter activity. NO release downregulates placental TAUT activity, and it has previously been shown that IUGR is associated with increased fetoplacental NO levels. NO may therefore play an important role in downregulating MVM TAUT activity in IUGR.
Ämne (baseras på Högskoleverkets indelning av forskningsämnen):
Medicinska grundvetenskaper ->
Adult, Blotting, Western, Carrier Proteins/biosynthesis/*metabolism, Cell Membrane/metabolism, Chorionic Villi/metabolism, Female, Fetal Growth Retardation/*metabolism, Gene Expression Regulation/*physiology, Humans, Immunohistochemistry, Immunosuppressive Agents/pharmacology, Membrane Glycoproteins/biosynthesis/*metabolism, *Membrane Transport Proteins, Placenta/cytology/*metabolism, Pregnancy, Protein Kinase C/biosynthesis, Research Support, Non-U.S. Gov't, Sirolimus/pharmacology, Sodium/physiology, Up-Regulation
Postens nummer:
Posten skapad:
2007-05-21 15:41
Posten ändrad:
2011-01-20 09:59

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