Amino acid transport systems β and A in fetal T lymphocytes in intrauterine growth restriction and with tumor necrosis factor-α treatment

Abstract

Intrauterine growth restriction (IUGR) is associated with reduced activity of placental amino acid transport systems β and A. Whether this phenotype is maintained in fetal cells outside the placenta is unknown. In IUGR, cord blood tumor necrosis factor (TNF)-α concentrations are raised, potentially influencing amino acid transport in fetal cells. We used fetal T lymphocytes as a model to study systems β and A amino acid transporters in IUGR compared with normal pregnancy. We also studied the effect of TNF-α on amino acid transporter activity. In fetal lymphocytes from IUGR pregnancies, taurine transporter mRNA expression encoding system β transporter was reduced, but there was no change in system β activity. No significant differences were observed in system A mRNA expression (encoding SNAT1 and SNAT2) or system A activity between the two groups. After 24 or 48 h TNF-α treatment, fetal T lymphocytes from normal pregnancies showed no significant change in system A or system β activity, although cell viability was compromised. This study represents the first characterization of amino acid transport in a fetal cell outside the placenta in IUGR. We conclude that the reduced amino acid transporter activity found in placenta in IUGR is not a feature of all fetal cells. Copyright © 2008 International Pediatric Research Foundation, Inc.