Taurine Transport in the in Vitro Perfused Human Placenta

Hibbard, Judith U.; Pridjian, Gabriella; Whitington, Peter F.; Moawad, Atef H.

doi:10.1203/00006450-199001000-00021

Cited by 25 publications

(12 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There is also the possibility is that the kinetic properties of system β are different between the maternal-facing plasma membrane of syncytiotrophoblast layer II of mouse placenta and human syncytiotrophoblast MVM. This suggestion is consistent with the observation that the affinity ( K m ) for this transport mechanism varies by more than two orders of magnitude between different tissues and species [47].…”

Section: Discussionsupporting

confidence: 92%

Isolation of Plasma Membrane Vesicles from Mouse Placenta at Term and Measurement of System A and System β Amino Acid Transporter Activity

et al. 2010

View full text Add to dashboard Cite

Placental amino acid transport is essential for optimal fetal growth and development, with a reduced fetal provision of amino acids being implicated as a potential cause of fetal growth restriction (FGR). Understanding placental insufficiency related FGR has been aided by the development of mouse models that have features of the human disease. However, to take maximal advantage of these, methods are required to study placental function in the mouse. Here, we report a method to isolate plasma membrane vesicles from mouse placenta near-term and have used these to investigate two amino acid transporters, systems A and β, the activities of which are reduced in human placental microvillous plasma membrane (MVM) vesicles from FGR pregnancies. Plasma membrane vesicles were isolated at embryonic day 18 by a protocol involving homogenisation, MgCl2 precipitation and centrifugation. Vesicles were enriched 11.3 ± 0.5-fold in alkaline phosphatase activity as compared to initial homogenate, with minimal intracellular organelle contamination as judged by marker analyses. Cytochemistry revealed alkaline phosphatase was localised between trophoblast layers I and II, with intense reaction product deposited on the maternal-facing plasma membrane of layer II, suggesting that vesicles were derived from this trophoblast membrane. System A and system β activity in mouse placental vesicles, measured as Na+-dependent uptake of 14C-methylaminoisobutyric acid (MeAIB) and 3H-taurine respectively confirmed localisation of these transporters to the maternal-facing plasma membrane of layer II. Comparison to human placental MVM showed that system A activity was comparable at initial rate between species whilst system β activity was significantly lower in mouse. This mirrored the lower expression of TAUT observed in mouse placental vesicles. We conclude that syncytiotrophoblast layer II-derived plasma membrane vesicles can be isolated and used to examine transporter function.

show abstract

Section: Discussionsupporting

confidence: 92%

Isolation of Plasma Membrane Vesicles from Mouse Placenta at Term and Measurement of System A and System β Amino Acid Transporter Activity

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Taurine is considered to be an essential amino acid during development, as the endogenous synthesis of taurine is inadequate in the human foetus (Hibbard et al . ). Thus, the foetus is dependent on the maternal supply of taurine.…”

Section: Physiological Role Of Taurinementioning

confidence: 97%

Physiological role of taurine – from organism to organelle

et al. 2014

View full text Add to dashboard Cite

Taurine is often referred to as a semi-essential amino acid as newborn mammals have a limited ability to synthesize taurine and have to rely on dietary supply. Taurine is not thought to be incorporated into proteins as no aminoacyl tRNA synthetase has yet been identified and is not oxidized in mammalian cells. However, taurine contributes significantly to the cellular pool of organic osmolytes and has accordingly been acknowledged for its role in cell volume restoration following osmotic perturbation. This review describes taurine homeostasis in cells and organelles with emphasis on taurine biophysics/membrane dynamics, regulation of transport proteins involved in active taurine uptake and passive taurine release as well as physiological processes, for example, development, lung function, mitochondrial function, antioxidative defence and apoptosis which seem to be affected by a shift in the expression of the taurine transporters and/or the cellular taurine content.

show abstract

“…The endogenous synthesis of taurine is inadequate in the fetus, and taurine is therefore considered to be an essential amino acid during fetal development (Hibbard et al 1990). Consequently, the fetus is dependent on placental transport, mediated by high‐affinity Na + ‐ and Cl − ‐dependent transporters (Ramamoorthy et al 1994), for an adequate supply of taurine.…”

mentioning

confidence: 99%

Maternal taurine supplementation in the late pregnant rat stimulates postnatal growth and induces obesity and insulin resistance in adult offspring

Hultman

Alexanderson

Mannerås

et al. 2007

The Journal of Physiology

View full text Add to dashboard Cite

An adequate supply of taurine during fetal life is important for normal beta-cell development and insulin action. An altered availability of taurine may programme glucose metabolism in utero and result in type 2 diabetes in adult age. We examined whether maternal taurine supplementation in late pregnant rats affects postnatal growth, adult body composition, insulin sensitivity and endogenous insulin secretion in intrauterine growth restricted (IUGR) and normal offspring. Uterine artery ligation or sham operations were performed on gestational day (GD) 19. Taurine supplementation was given to half of the dams from GD 18 until term, resulting in four groups of offspring: sham (n = 22), sham/taurine (n = 22), IUGR (n = 22) and IUGR/taurine (n = 24). The offspring were studied at 12 weeks of age. In offspring with normal birth weight, fetal taurine supplementation markedly stimulated postnatal growth. In sham/taurine females, fat depots, plasma free fatty acid and leptin concentrations were increased, and insulin sensitivity was reduced. Insulin sensitivity was unaltered in IUGR and IUGR/taurine offspring. However, whereas IUGR offspring showed little catch-up growth, 50% of IUGR/ taurine animals displayed complete catch-up at 12 weeks of age, and these animals had increased fat depots and reduced insulin sensitivity. In conclusion, taurine supplementation in late gestation resulted in accelerated postnatal growth, which was associated with adult obesity and insulin resistance in both IUGR and normal offspring. This effect was particularly evident in females. These data suggest that fetal taurine availability is an important determinant for postnatal growth, insulin sensitivity and fat accumulation.

show abstract

Taurine Transport in the in Vitro Perfused Human Placenta

Cited by 25 publications

References 36 publications

Isolation of Plasma Membrane Vesicles from Mouse Placenta at Term and Measurement of System A and System β Amino Acid Transporter Activity

Isolation of Plasma Membrane Vesicles from Mouse Placenta at Term and Measurement of System A and System β Amino Acid Transporter Activity

Physiological role of taurine – from organism to organelle

Maternal taurine supplementation in the late pregnant rat stimulates postnatal growth and induces obesity and insulin resistance in adult offspring

Contact Info

Product

Resources

About