Anionic amino acid transporter expression in late gestation rodent yolk sac

The yolk sac plays an important role in fetal nutrition. Transport of amino acids by the rodent visceral yolk sac has been shown previously. We have demonstrated the presence of several amino acid transport proteins capable of the Na(+)-dependent transport of anionic amino acids within late gestation mouse visceral yolk sac and uterine epithelium. We speculate that these proteins may be involved in the efflux of glutamate from the fetal to the maternal circulations.